Cross-site Scripting in Prism
Description
Prism is a syntax highlighting library. Starting with version 1.14.0 and prior to version 1.27.0, Prism's command line plugin can be used by attackers to achieve a cross-site scripting attack. The command line plugin did not properly escape its output, leading to the input text being inserted into the DOM as HTML code. Server-side usage of Prism is not impacted. Websites that do not use the Command Line plugin are also not impacted. This bug has been fixed in v1.27.0. As a workaround, do not use the command line plugin on untrusted inputs, or sanitize all code blocks (remove all HTML code text) from all code blocks that use the command line plugin.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
prismjsnpm | >= 1.14.0, < 1.27.0 | 1.27.0 |
Affected products
1Patches
1e002e78c3431Command Line: Escape markup in command line output (#3341)
2 files changed · +4 −2
plugins/command-line/prism-command-line.js+3 −1 modified@@ -143,8 +143,10 @@ for (var i = 0, l = codeLines.length; i < l; i++) { // Add spans to allow distinction of input/output text for styling if (outputLines.hasOwnProperty(i)) { + // outputLines were removed from codeLines so missed out on escaping + // of markup so do it here. codeLines[i] = '<span class="token output">' - + outputLines[i] + '</span>'; + + Prism.util.encode(outputLines[i]) + '</span>'; } else { codeLines[i] = '<span class="token command">' + codeLines[i] + '</span>';
plugins/command-line/prism-command-line.min.js+1 −1 modified@@ -1 +1 @@ -!function(){if("undefined"!=typeof Prism&&"undefined"!=typeof document){var v=/(?:^|\s)command-line(?:\s|$)/,g="command-line-prompt",p="".startsWith?function(e,t){return e.startsWith(t)}:function(e,t){return 0===e.indexOf(t)},d="".endsWith?function(e,t){return e.endsWith(t)}:function(e,t){var n=e.length;return e.substring(n-t.length,n)===t};Prism.hooks.add("before-highlight",function(e){var t=N(e);if(!t.complete&&e.code){var n=e.element.parentElement;if(n&&/pre/i.test(n.nodeName)&&(v.test(n.className)||v.test(e.element.className))){var a=e.element.querySelector("."+g);a&&a.remove();var i=e.code.split("\n"),r=t.continuationLineIndicies=new Set,s=n.getAttribute("data-continuation-str");if(s&&1<i.length)for(var o=1;o<i.length;o++)i.hasOwnProperty(o-1)&&d(i[o-1],s)&&r.add(o);t.numberOfLines=i.length;var l=t.outputLines=[],m=n.getAttribute("data-output"),u=n.getAttribute("data-filter-output");if(null!==m)m.split(",").forEach(function(e){var t=e.split("-"),n=parseInt(t[0],10),a=2===t.length?parseInt(t[1],10):n;if(!isNaN(n)&&!isNaN(a)){n<1&&(n=1),a>i.length&&(a=i.length),a--;for(var r=--n;r<=a;r++)l[r]=i[r],i[r]=""}});else if(u)for(var c=0;c<i.length;c++)p(i[c],u)&&(l[c]=i[c].slice(u.length),i[c]="");e.code=i.join("\n")}else t.complete=!0}else t.complete=!0}),Prism.hooks.add("before-insert",function(e){var t=N(e);if(!t.complete){for(var n=e.highlightedCode.split("\n"),a=t.outputLines||[],r=0,i=n.length;r<i;r++)a.hasOwnProperty(r)?n[r]='<span class="token output">'+a[r]+"</span>":n[r]='<span class="token command">'+n[r]+"</span>";e.highlightedCode=n.join("\n")}}),Prism.hooks.add("complete",function(e){if(function(e){return"command-line"in(e.vars=e.vars||{})}(e)){var t=N(e);if(!t.complete){var n=e.element.parentElement;v.test(e.element.className)&&(e.element.className=e.element.className.replace(v," ")),v.test(n.className)||(n.className+=" command-line");var a,r="",i=t.numberOfLines||0,s=h("data-prompt","");if(""!==s)a='<span data-prompt="'+s+'"></span>';else a='<span data-user="'+h("data-user","user")+'" data-host="'+h("data-host","localhost")+'"></span>';for(var o=t.continuationLineIndicies||new Set,l='<span data-continuation-prompt="'+h("data-continuation-prompt",">")+'"></span>',m=0;m<i;m++)o.has(m)?r+=l:r+=a;var u=document.createElement("span");u.className=g,u.innerHTML=r;for(var c=t.outputLines||[],p=0,d=c.length;p<d;p++)if(c.hasOwnProperty(p)){var f=u.children[p];f.removeAttribute("data-user"),f.removeAttribute("data-host"),f.removeAttribute("data-prompt")}e.element.insertBefore(u,e.element.firstChild),t.complete=!0}}function h(e,t){return(n.getAttribute(e)||t).replace(/"/g,""")}})}function N(e){var t=e.vars=e.vars||{};return t["command-line"]=t["command-line"]||{}}}(); \ No newline at end of file +!function(){if("undefined"!=typeof Prism&&"undefined"!=typeof document){var v=/(?:^|\s)command-line(?:\s|$)/,g="command-line-prompt",p="".startsWith?function(e,t){return e.startsWith(t)}:function(e,t){return 0===e.indexOf(t)},d="".endsWith?function(e,t){return e.endsWith(t)}:function(e,t){var n=e.length;return e.substring(n-t.length,n)===t};Prism.hooks.add("before-highlight",function(e){var t=N(e);if(!t.complete&&e.code){var n=e.element.parentElement;if(n&&/pre/i.test(n.nodeName)&&(v.test(n.className)||v.test(e.element.className))){var a=e.element.querySelector("."+g);a&&a.remove();var i=e.code.split("\n"),r=t.continuationLineIndicies=new Set,s=n.getAttribute("data-continuation-str");if(s&&1<i.length)for(var o=1;o<i.length;o++)i.hasOwnProperty(o-1)&&d(i[o-1],s)&&r.add(o);t.numberOfLines=i.length;var l=t.outputLines=[],m=n.getAttribute("data-output"),u=n.getAttribute("data-filter-output");if(null!==m)m.split(",").forEach(function(e){var t=e.split("-"),n=parseInt(t[0],10),a=2===t.length?parseInt(t[1],10):n;if(!isNaN(n)&&!isNaN(a)){n<1&&(n=1),a>i.length&&(a=i.length),a--;for(var r=--n;r<=a;r++)l[r]=i[r],i[r]=""}});else if(u)for(var c=0;c<i.length;c++)p(i[c],u)&&(l[c]=i[c].slice(u.length),i[c]="");e.code=i.join("\n")}else t.complete=!0}else t.complete=!0}),Prism.hooks.add("before-insert",function(e){var t=N(e);if(!t.complete){for(var n=e.highlightedCode.split("\n"),a=t.outputLines||[],r=0,i=n.length;r<i;r++)a.hasOwnProperty(r)?n[r]='<span class="token output">'+Prism.util.encode(a[r])+"</span>":n[r]='<span class="token command">'+n[r]+"</span>";e.highlightedCode=n.join("\n")}}),Prism.hooks.add("complete",function(e){if(function(e){return"command-line"in(e.vars=e.vars||{})}(e)){var t=N(e);if(!t.complete){var n=e.element.parentElement;v.test(e.element.className)&&(e.element.className=e.element.className.replace(v," ")),v.test(n.className)||(n.className+=" command-line");var a,r="",i=t.numberOfLines||0,s=h("data-prompt","");if(""!==s)a='<span data-prompt="'+s+'"></span>';else a='<span data-user="'+h("data-user","user")+'" data-host="'+h("data-host","localhost")+'"></span>';for(var o=t.continuationLineIndicies||new Set,l='<span data-continuation-prompt="'+h("data-continuation-prompt",">")+'"></span>',m=0;m<i;m++)o.has(m)?r+=l:r+=a;var u=document.createElement("span");u.className=g,u.innerHTML=r;for(var c=t.outputLines||[],p=0,d=c.length;p<d;p++)if(c.hasOwnProperty(p)){var f=u.children[p];f.removeAttribute("data-user"),f.removeAttribute("data-host"),f.removeAttribute("data-prompt")}e.element.insertBefore(u,e.element.firstChild),t.complete=!0}}function h(e,t){return(n.getAttribute(e)||t).replace(/"/g,""")}})}function N(e){var t=e.vars=e.vars||{};return t["command-line"]=t["command-line"]||{}}}(); \ No newline at end of file
Vulnerability mechanics
Generated by null/stub on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.
References
5- github.com/advisories/GHSA-3949-f494-cm99ghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2022-23647ghsaADVISORY
- github.com/PrismJS/prism/commit/e002e78c343154e1c0ddf9d6a0bb85689e1a5c7cghsax_refsource_MISCWEB
- github.com/PrismJS/prism/pull/3341ghsax_refsource_MISCWEB
- github.com/PrismJS/prism/security/advisories/GHSA-3949-f494-cm99ghsax_refsource_CONFIRMWEB
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