diff --git a/go.mod b/go.mod
index 8b1135921..af6733717 100644
--- a/go.mod
+++ b/go.mod
@@ -86,7 +86,7 @@ require (
 	github.com/mgechev/revive v1.0.3
 	github.com/mholt/acmez v0.1.3 // indirect
 	github.com/mholt/archiver/v3 v3.5.0
-	github.com/microcosm-cc/bluemonday v1.0.5
+	github.com/microcosm-cc/bluemonday v1.0.6
 	github.com/miekg/dns v1.1.40 // indirect
 	github.com/minio/md5-simd v1.1.2 // indirect
 	github.com/minio/minio-go/v7 v7.0.10
@@ -136,7 +136,7 @@ require (
 	go.uber.org/multierr v1.6.0 // indirect
 	go.uber.org/zap v1.16.0 // indirect
 	golang.org/x/crypto v0.0.0-20210220033148-5ea612d1eb83
-	golang.org/x/net v0.0.0-20210331212208-0fccb6fa2b5c
+	golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4
 	golang.org/x/oauth2 v0.0.0-20210220000619-9bb904979d93
 	golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44
 	golang.org/x/text v0.3.5
@@ -153,5 +153,3 @@ require (
 )
 
 replace github.com/hashicorp/go-version => github.com/6543/go-version v1.2.4
-
-replace github.com/microcosm-cc/bluemonday => github.com/lunny/bluemonday v1.0.5-0.20201227154428-ca34796141e8
diff --git a/go.sum b/go.sum
index 9526a8116..68a3fe1c4 100644
--- a/go.sum
+++ b/go.sum
@@ -196,8 +196,6 @@ github.com/cespare/xxhash/v2 v2.1.1 h1:6MnRN8NT7+YBpUIWxHtefFZOKTAPgGjpQSxqLNn0+
 github.com/cespare/xxhash/v2 v2.1.1/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/chi-middleware/proxy v1.1.1 h1:4HaXUp8o2+bhHr1OhVy+VjN0+L7/07JDcn6v7YrTjrQ=
 github.com/chi-middleware/proxy v1.1.1/go.mod h1:jQwMEJct2tz9VmtCELxvnXoMfa+SOdikvbVJVHv/M+0=
-github.com/chris-ramon/douceur v0.2.0 h1:IDMEdxlEUUBYBKE4z/mJnFyVXox+MjuEVDJNN27glkU=
-github.com/chris-ramon/douceur v0.2.0/go.mod h1:wDW5xjJdeoMm1mRt4sD4c/LbF/mWdEpRXQKjTR8nIBE=
 github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
 github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
 github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
@@ -776,8 +774,6 @@ github.com/libdns/libdns v0.2.0 h1:ewg3ByWrdUrxrje8ChPVMBNcotg7H9LQYg+u5De2RzI=
 github.com/libdns/libdns v0.2.0/go.mod h1:yQCXzk1lEZmmCPa857bnk4TsOiqYasqpyOEeSObbb40=
 github.com/lightstep/lightstep-tracer-common/golang/gogo v0.0.0-20190605223551-bc2310a04743/go.mod h1:qklhhLq1aX+mtWk9cPHPzaBjWImj5ULL6C7HFJtXQMM=
 github.com/lightstep/lightstep-tracer-go v0.18.1/go.mod h1:jlF1pusYV4pidLvZ+XD0UBX0ZE6WURAspgAczcDHrL4=
-github.com/lunny/bluemonday v1.0.5-0.20201227154428-ca34796141e8 h1:1omo92DLtxQu6VwVPSZAmduHaK5zssed6cvkHyl1XOg=
-github.com/lunny/bluemonday v1.0.5-0.20201227154428-ca34796141e8/go.mod h1:8iwZnFn2CDDNZ0r6UXhF4xawGvzaqzCRa1n3/lO3W2w=
 github.com/lunny/dingtalk_webhook v0.0.0-20171025031554-e3534c89ef96 h1:uNwtsDp7ci48vBTTxDuwcoTXz4lwtDTe7TjCQ0noaWY=
 github.com/lunny/dingtalk_webhook v0.0.0-20171025031554-e3534c89ef96/go.mod h1:mmIfjCSQlGYXmJ95jFN84AkQFnVABtKuJL8IrzwvUKQ=
 github.com/lunny/log v0.0.0-20160921050905-7887c61bf0de/go.mod h1:3q8WtuPQsoRbatJuy3nvq/hRSvuBJrHHr+ybPPiNvHQ=
@@ -834,6 +830,8 @@ github.com/mholt/acmez v0.1.3 h1:J7MmNIk4Qf9b8mAGqAh4XkNeowv3f1zW816yf4zt7Qk=
 github.com/mholt/acmez v0.1.3/go.mod h1:8qnn8QA/Ewx8E3ZSsmscqsIjhhpxuy9vqdgbX2ceceM=
 github.com/mholt/archiver/v3 v3.5.0 h1:nE8gZIrw66cu4osS/U7UW7YDuGMHssxKutU8IfWxwWE=
 github.com/mholt/archiver/v3 v3.5.0/go.mod h1:qqTTPUK/HZPFgFQ/TJ3BzvTpF/dPtFVJXdQbCmeMxwc=
+github.com/microcosm-cc/bluemonday v1.0.6 h1:ZOvqHKtnx0fUpnbQm3m3zKFWE+DRC+XB1onh8JoEObE=
+github.com/microcosm-cc/bluemonday v1.0.6/go.mod h1:HOT/6NaBlR0f9XlxD3zolN6Z3N8Lp4pvhp+jLS5ihnI=
 github.com/miekg/dns v1.0.14/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
 github.com/miekg/dns v1.1.30/go.mod h1:KNUDUusw/aVsxyTYZM1oqvCicbwhgbNgztCETuNZ7xM=
 github.com/miekg/dns v1.1.40 h1:pyyPFfGMnciYUk/mXpKkVmeMQjfXqt3FAJ2hy7tPiLA=
@@ -1321,8 +1319,9 @@ golang.org/x/net v0.0.0-20201202161906-c7110b5ffcbb/go.mod h1:sp8m0HH+o8qH0wwXwY
 golang.org/x/net v0.0.0-20201209123823-ac852fbbde11/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20201224014010-6772e930b67b/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20210119194325-5f4716e94777/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.0.0-20210331212208-0fccb6fa2b5c h1:KHUzaHIpjWVlVVNh65G3hhuj3KB1HnjY6Cq5cTvRQT8=
 golang.org/x/net v0.0.0-20210331212208-0fccb6fa2b5c/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
+golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4 h1:4nGaVu0QrbjT/AK2PRLuQfQuh6DJve+pELhqTdAj3x0=
+golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20181106182150-f42d05182288/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
diff --git a/modules/markup/sanitizer.go b/modules/markup/sanitizer.go
index 19feaa3cc..9f336d833 100644
--- a/modules/markup/sanitizer.go
+++ b/modules/markup/sanitizer.go
@@ -46,7 +46,9 @@ func ReplaceSanitizer() {
 	sanitizer.policy.AllowAttrs("checked", "disabled").OnElements("input")
 
 	// Custom URL-Schemes
-	sanitizer.policy.AllowURLSchemes(setting.Markdown.CustomURLSchemes...)
+	if len(setting.Markdown.CustomURLSchemes) > 0 {
+		sanitizer.policy.AllowURLSchemes(setting.Markdown.CustomURLSchemes...)
+	}
 
 	// Allow keyword markup
 	sanitizer.policy.AllowAttrs("class").Matching(regexp.MustCompile(`^` + keywordClass + `$`)).OnElements("span")
diff --git a/modules/markup/sanitizer_test.go b/modules/markup/sanitizer_test.go
index 63b70166d..9e173015d 100644
--- a/modules/markup/sanitizer_test.go
+++ b/modules/markup/sanitizer_test.go
@@ -6,6 +6,8 @@
 package markup
 
 import (
+	"html/template"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -50,3 +52,13 @@ func Test_Sanitizer(t *testing.T) {
 		assert.Equal(t, testCases[i+1], string(SanitizeBytes([]byte(testCases[i]))))
 	}
 }
+
+func TestSanitizeNonEscape(t *testing.T) {
+	descStr := "<scrİpt>&lt;script&gt;alert(document.domain)&lt;/script&gt;</scrİpt>"
+
+	output := template.HTML(Sanitize(string(descStr)))
+	if strings.Contains(string(output), "<script>") {
+		t.Errorf("un-escaped <script> in output: %q", output)
+	}
+
+}
diff --git a/vendor/github.com/chris-ramon/douceur/parser/parser.go b/vendor/github.com/aymerick/douceur/parser/parser.go
similarity index 100%
rename from vendor/github.com/chris-ramon/douceur/parser/parser.go
rename to vendor/github.com/aymerick/douceur/parser/parser.go
diff --git a/vendor/github.com/chris-ramon/douceur/LICENSE b/vendor/github.com/chris-ramon/douceur/LICENSE
deleted file mode 100644
index 6ce87cd37..000000000
--- a/vendor/github.com/chris-ramon/douceur/LICENSE
+++ /dev/null
@@ -1,22 +0,0 @@
-The MIT License (MIT)
-
-Copyright (c) 2015 Aymerick JEHANNE
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
-
diff --git a/vendor/github.com/microcosm-cc/bluemonday/SECURITY.md b/vendor/github.com/microcosm-cc/bluemonday/SECURITY.md
new file mode 100644
index 000000000..a344e7c05
--- /dev/null
+++ b/vendor/github.com/microcosm-cc/bluemonday/SECURITY.md
@@ -0,0 +1,15 @@
+# Security Policy
+
+## Supported Versions
+
+Latest tag and tip are supported.
+
+Older tags remain present but changes result in new tags and are not back ported... please verify any issue against the latest tag and tip.
+
+## Reporting a Vulnerability
+
+Email: <bluemonday@buro9.com>
+
+Bluemonday is pure OSS and not maintained by a company. As such there is no bug bounty program but security issues will be taken seriously and resolved as soon as possible.
+
+The maintainer lives in the United Kingdom and whilst the email is monitored expect a reply or ACK when the maintainer is awake.
diff --git a/vendor/github.com/microcosm-cc/bluemonday/go.mod b/vendor/github.com/microcosm-cc/bluemonday/go.mod
index 47b521a75..0ff3d77b0 100644
--- a/vendor/github.com/microcosm-cc/bluemonday/go.mod
+++ b/vendor/github.com/microcosm-cc/bluemonday/go.mod
@@ -1,10 +1,9 @@
 module github.com/microcosm-cc/bluemonday
 
-go 1.9
+go 1.16
 
 require (
-	github.com/aymerick/douceur v0.2.0 // indirect
-	github.com/chris-ramon/douceur v0.2.0
+	github.com/aymerick/douceur v0.2.0
 	github.com/gorilla/css v1.0.0 // indirect
-	golang.org/x/net v0.0.0-20181220203305-927f97764cc3
+	golang.org/x/net v0.0.0-20210331212208-0fccb6fa2b5c
 )
diff --git a/vendor/github.com/microcosm-cc/bluemonday/go.sum b/vendor/github.com/microcosm-cc/bluemonday/go.sum
index 8c34e7a40..7955d9eb0 100644
--- a/vendor/github.com/microcosm-cc/bluemonday/go.sum
+++ b/vendor/github.com/microcosm-cc/bluemonday/go.sum
@@ -1,8 +1,11 @@
 github.com/aymerick/douceur v0.2.0 h1:Mv+mAeH1Q+n9Fr+oyamOlAkUNPWPlA8PPGR0QAaYuPk=
 github.com/aymerick/douceur v0.2.0/go.mod h1:wlT5vV2O3h55X9m7iVYN0TBM0NH/MmbLnd30/FjWUq4=
-github.com/chris-ramon/douceur v0.2.0 h1:IDMEdxlEUUBYBKE4z/mJnFyVXox+MjuEVDJNN27glkU=
-github.com/chris-ramon/douceur v0.2.0/go.mod h1:wDW5xjJdeoMm1mRt4sD4c/LbF/mWdEpRXQKjTR8nIBE=
 github.com/gorilla/css v1.0.0 h1:BQqNyPTi50JCFMTw/b67hByjMVXZRwGha6wxVGkeihY=
 github.com/gorilla/css v1.0.0/go.mod h1:Dn721qIggHpt4+EFCcTLTU/vk5ySda2ReITrtgBl60c=
-golang.org/x/net v0.0.0-20181220203305-927f97764cc3 h1:eH6Eip3UpmR+yM/qI9Ijluzb1bNv/cAU/n+6l8tRSis=
-golang.org/x/net v0.0.0-20181220203305-927f97764cc3/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20210331212208-0fccb6fa2b5c h1:KHUzaHIpjWVlVVNh65G3hhuj3KB1HnjY6Cq5cTvRQT8=
+golang.org/x/net v0.0.0-20210331212208-0fccb6fa2b5c/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
diff --git a/vendor/github.com/microcosm-cc/bluemonday/handlers.go b/vendor/github.com/microcosm-cc/bluemonday/handlers.go
index 1ef4c8acd..9753d6e95 100644
--- a/vendor/github.com/microcosm-cc/bluemonday/handlers.go
+++ b/vendor/github.com/microcosm-cc/bluemonday/handlers.go
@@ -26,6 +26,7 @@
 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
 package bluemonday
 
 import (
diff --git a/vendor/github.com/microcosm-cc/bluemonday/policy.go b/vendor/github.com/microcosm-cc/bluemonday/policy.go
index 739d302c3..9c7e662fc 100644
--- a/vendor/github.com/microcosm-cc/bluemonday/policy.go
+++ b/vendor/github.com/microcosm-cc/bluemonday/policy.go
@@ -69,6 +69,9 @@ type Policy struct {
 	// Will skip for href="/foo" or href="foo"
 	requireNoReferrerFullyQualifiedLinks bool
 
+	// When true, add crossorigin="anonymous" to HTML audio, img, link, script, and video tags
+	requireCrossOriginAnonymous bool
+
 	// When true add target="_blank" to fully qualified links
 	// Will add for href="http://foo"
 	// Will skip for href="/foo" or href="foo"
@@ -433,25 +436,25 @@ func (spb *stylePolicyBuilder) OnElements(elements ...string) *Policy {
 // and return the updated policy
 func (spb *stylePolicyBuilder) OnElementsMatching(regex *regexp.Regexp) *Policy {
 
-		for _, attr := range spb.propertyNames {
+	for _, attr := range spb.propertyNames {
 
-			if _, ok := spb.p.elsMatchingAndStyles[regex]; !ok {
-				spb.p.elsMatchingAndStyles[regex] = make(map[string]stylePolicy)
-			}
-
-			sp := stylePolicy{}
-			if spb.handler != nil {
-				sp.handler = spb.handler
-			} else if len(spb.enum) > 0 {
-				sp.enum = spb.enum
-			} else if spb.regexp != nil {
-				sp.regexp = spb.regexp
-			} else {
-				sp.handler = getDefaultHandler(attr)
-			}
-			spb.p.elsMatchingAndStyles[regex][attr] = sp
+		if _, ok := spb.p.elsMatchingAndStyles[regex]; !ok {
+			spb.p.elsMatchingAndStyles[regex] = make(map[string]stylePolicy)
 		}
 
+		sp := stylePolicy{}
+		if spb.handler != nil {
+			sp.handler = spb.handler
+		} else if len(spb.enum) > 0 {
+			sp.enum = spb.enum
+		} else if spb.regexp != nil {
+			sp.regexp = spb.regexp
+		} else {
+			sp.handler = getDefaultHandler(attr)
+		}
+		spb.p.elsMatchingAndStyles[regex][attr] = sp
+	}
+
 	return spb.p
 }
 
@@ -558,6 +561,16 @@ func (p *Policy) RequireNoReferrerOnFullyQualifiedLinks(require bool) *Policy {
 	return p
 }
 
+// RequireCrossOriginAnonymous will result in all audio, img, link, script, and
+// video tags having a crossorigin="anonymous" added to them if one does not
+// already exist
+func (p *Policy) RequireCrossOriginAnonymous(require bool) *Policy {
+
+	p.requireCrossOriginAnonymous = require
+
+	return p
+}
+
 // AddTargetBlankToFullyQualifiedLinks will result in all a, area and link tags
 // that point to a non-local destination (i.e. starts with a protocol and has a
 // host) having a target="_blank" added to them if one does not already exist
diff --git a/vendor/github.com/microcosm-cc/bluemonday/sanitize.go b/vendor/github.com/microcosm-cc/bluemonday/sanitize.go
index a58333aa6..99559bbab 100644
--- a/vendor/github.com/microcosm-cc/bluemonday/sanitize.go
+++ b/vendor/github.com/microcosm-cc/bluemonday/sanitize.go
@@ -39,7 +39,7 @@ import (
 
 	"golang.org/x/net/html"
 
-	cssparser "github.com/chris-ramon/douceur/parser"
+	"github.com/aymerick/douceur/parser"
 )
 
 var (
@@ -286,7 +286,7 @@ func (p *Policy) sanitize(r io.Reader) *bytes.Buffer {
 
 		case html.StartTagToken:
 
-			mostRecentlyStartedToken = strings.ToLower(token.Data)
+			mostRecentlyStartedToken = normaliseElementName(token.Data)
 
 			aps, ok := p.elsAndAttrs[token.Data]
 			if !ok {
@@ -329,7 +329,7 @@ func (p *Policy) sanitize(r io.Reader) *bytes.Buffer {
 
 		case html.EndTagToken:
 
-			if mostRecentlyStartedToken == strings.ToLower(token.Data) {
+			if mostRecentlyStartedToken == normaliseElementName(token.Data) {
 				mostRecentlyStartedToken = ""
 			}
 
@@ -407,11 +407,11 @@ func (p *Policy) sanitize(r io.Reader) *bytes.Buffer {
 
 			if !skipElementContent {
 				switch mostRecentlyStartedToken {
-				case "script":
+				case `script`:
 					// not encouraged, but if a policy allows JavaScript we
 					// should not HTML escape it as that would break the output
 					buff.WriteString(token.Data)
-				case "style":
+				case `style`:
 					// not encouraged, but if a policy allows CSS styles we
 					// should not HTML escape it as that would break the output
 					buff.WriteString(token.Data)
@@ -721,6 +721,26 @@ func (p *Policy) sanitizeAttrs(
 		}
 	}
 
+	if p.requireCrossOriginAnonymous && len(cleanAttrs) > 0 {
+		switch elementName {
+		case "audio", "img", "link", "script", "video":
+			var crossOriginFound bool
+			for _, htmlAttr := range cleanAttrs {
+				if htmlAttr.Key == "crossorigin" {
+					crossOriginFound = true
+					htmlAttr.Val = "anonymous"
+				}
+			}
+
+			if !crossOriginFound {
+				crossOrigin := html.Attribute{}
+				crossOrigin.Key = "crossorigin"
+				crossOrigin.Val = "anonymous"
+				cleanAttrs = append(cleanAttrs, crossOrigin)
+			}
+		}
+	}
+
 	return cleanAttrs
 }
 
@@ -744,7 +764,7 @@ func (p *Policy) sanitizeStyles(attr html.Attribute, elementName string) html.At
 	if len(attr.Val) > 0 && attr.Val[len(attr.Val)-1] != ';' {
 		attr.Val = attr.Val + ";"
 	}
-	decs, err := cssparser.ParseDeclarations(attr.Val)
+	decs, err := parser.ParseDeclarations(attr.Val)
 	if err != nil {
 		attr.Val = ""
 		return attr
@@ -944,3 +964,23 @@ func (p *Policy) matchRegex(elementName string) (map[string]attrPolicy, bool) {
 	}
 	return aps, matched
 }
+
+
+// normaliseElementName takes a HTML element like <script> which is user input
+// and returns a lower case version of it that is immune to UTF-8 to ASCII
+// conversion tricks (like the use of upper case cyrillic i scrİpt which a
+// strings.ToLower would convert to script). Instead this func will preserve
+// all non-ASCII as their escaped equivalent, i.e. \u0130 which reveals the
+// characters when lower cased
+func normaliseElementName(str string) string {
+	// that useful QuoteToASCII put quote marks at the start and end
+	// so those are trimmed off
+	return strings.TrimSuffix(
+		strings.TrimPrefix(
+			strings.ToLower(
+				strconv.QuoteToASCII(str),
+			),
+			`"`),
+		`"`,
+	)
+}
\ No newline at end of file
diff --git a/vendor/golang.org/x/net/internal/socket/rawconn.go b/vendor/golang.org/x/net/internal/socket/rawconn.go
index b07b89005..87e81071c 100644
--- a/vendor/golang.org/x/net/internal/socket/rawconn.go
+++ b/vendor/golang.org/x/net/internal/socket/rawconn.go
@@ -17,18 +17,45 @@ type Conn struct {
 	c       syscall.RawConn
 }
 
+// tcpConn is an interface implemented by net.TCPConn.
+// It can be used for interface assertions to check if a net.Conn is a TCP connection.
+type tcpConn interface {
+	SyscallConn() (syscall.RawConn, error)
+	SetLinger(int) error
+}
+
+var _ tcpConn = (*net.TCPConn)(nil)
+
+// udpConn is an interface implemented by net.UDPConn.
+// It can be used for interface assertions to check if a net.Conn is a UDP connection.
+type udpConn interface {
+	SyscallConn() (syscall.RawConn, error)
+	ReadMsgUDP(b, oob []byte) (n, oobn, flags int, addr *net.UDPAddr, err error)
+}
+
+var _ udpConn = (*net.UDPConn)(nil)
+
+// ipConn is an interface implemented by net.IPConn.
+// It can be used for interface assertions to check if a net.Conn is an IP connection.
+type ipConn interface {
+	SyscallConn() (syscall.RawConn, error)
+	ReadMsgIP(b, oob []byte) (n, oobn, flags int, addr *net.IPAddr, err error)
+}
+
+var _ ipConn = (*net.IPConn)(nil)
+
 // NewConn returns a new raw connection.
 func NewConn(c net.Conn) (*Conn, error) {
 	var err error
 	var cc Conn
 	switch c := c.(type) {
-	case *net.TCPConn:
+	case tcpConn:
 		cc.network = "tcp"
 		cc.c, err = c.SyscallConn()
-	case *net.UDPConn:
+	case udpConn:
 		cc.network = "udp"
 		cc.c, err = c.SyscallConn()
-	case *net.IPConn:
+	case ipConn:
 		cc.network = "ip"
 		cc.c, err = c.SyscallConn()
 	default:
diff --git a/vendor/modules.txt b/vendor/modules.txt
index a0111a24a..e0509e0a2 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -92,6 +92,7 @@ github.com/anmitsu/go-shlex
 github.com/asaskevich/govalidator
 # github.com/aymerick/douceur v0.2.0
 github.com/aymerick/douceur/css
+github.com/aymerick/douceur/parser
 # github.com/beorn7/perks v1.0.1
 github.com/beorn7/perks/quantile
 # github.com/blevesearch/bleve/v2 v2.0.2
@@ -178,8 +179,6 @@ github.com/cespare/xxhash/v2
 # github.com/chi-middleware/proxy v1.1.1
 ## explicit
 github.com/chi-middleware/proxy
-# github.com/chris-ramon/douceur v0.2.0
-github.com/chris-ramon/douceur/parser
 # github.com/couchbase/go-couchbase v0.0.0-20210224140812-5740cd35f448
 ## explicit
 github.com/couchbase/go-couchbase
@@ -597,7 +596,7 @@ github.com/mholt/acmez/acme
 # github.com/mholt/archiver/v3 v3.5.0
 ## explicit
 github.com/mholt/archiver/v3
-# github.com/microcosm-cc/bluemonday v1.0.5 => github.com/lunny/bluemonday v1.0.5-0.20201227154428-ca34796141e8
+# github.com/microcosm-cc/bluemonday v1.0.6
 ## explicit
 github.com/microcosm-cc/bluemonday
 # github.com/miekg/dns v1.1.40
@@ -891,7 +890,7 @@ golang.org/x/crypto/ssh/knownhosts
 # golang.org/x/mod v0.4.1
 golang.org/x/mod/module
 golang.org/x/mod/semver
-# golang.org/x/net v0.0.0-20210331212208-0fccb6fa2b5c
+# golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4
 ## explicit
 golang.org/x/net/bpf
 golang.org/x/net/context
@@ -1065,4 +1064,3 @@ xorm.io/xorm/names
 xorm.io/xorm/schemas
 xorm.io/xorm/tags
 # github.com/hashicorp/go-version => github.com/6543/go-version v1.2.4
-# github.com/microcosm-cc/bluemonday => github.com/lunny/bluemonday v1.0.5-0.20201227154428-ca34796141e8