GHSA-c5v8-2q4r-5w9v is a critical-severity (CVSS 9.9) Cross-site Scripting (XSS) vulnerability in org.xwiki.platform:xwiki-platform-mentions-ui. 2 public exploit references exist, so weaponization risk is real. A fix is available for org.xwiki.platform:xwiki-platform-mentions-ui — see the affected versions and patch details below.
XWiki Platform Mentions UI vulnerable to Cross-site Scripting
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-c5v8-2q4r-5w9v.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-c5v8-2q4r-5w9v plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE sits: patch-first territory.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.xwiki.platform:xwiki-platform-mentions-ui☕org.xwiki.platform:xwiki-platform-mentions-uiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Impact
It's possible to store Javascript or groovy scripts in an mention macro anchor or reference field. The stored code is executed by anyone visiting the page with the mention.
For example, the example below will create a file at /tmp/exploit.txt:
{{mention reference="XWiki.Translation" anchor="{{/html~}~}{{async async=~"true~" cached=~"false~" context=~"doc.reference~"~}~}{{groovy~}~}new File(~"/tmp/exploit.txt~").withWriter { out -> out.println(~"owned!~"); }{{/groovy~}~}{{/async~}~}"/}}
Patches
This issue has been patched on XWiki 14.4 and 13.10.6.
Workarounds
It's possible to fix the vulnerability by updating XWiki.Mentions.MentionsMacro and edit the Macro code field of the XWiki.WikiMacroClass XObject.
<a id="$anchor" class="$stringtool.join($cssClasses, ' ')" data-reference="$services.model.serialize($reference.reference, 'default')" href="$link">$content</a>
Must be replaced by
<a id="$escapetool.xml($anchor)" class="$stringtool.join($cssClasses, ' ')" data-reference="$escapetool.xml($services.model.serialize($reference.reference, 'default'))" href="$escapetool.xml($link)">
$escapetool.xml($content)
</a>
See the patches:
- 14.4: https://github.com/xwiki/xwiki-platform/commit/4f290d87a8355e967378a1ed6aee23a06ba162eb
- 13.10.6: https://github.com/xwiki/xwiki-platform/commit/4032dc896857597efd169966dc9e2752a9fdd459#diff-4fe22885f772e47d3561a05348f73921669ec12d4413b220383b73c7ae484bc4R608-R610
References
For more information
If you have any questions or comments about this advisory:
- Open an issue in Jira XWiki.org
- Email us at Security Mailing List
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.xwiki.platform:xwiki-platform-mentions-ui | ≥ 12.5-rc-1&&< 13.10.6 | 13.10.6org.xwiki.platform:xwiki-platform-mentions-ui:13.10.6 |
| ☕Maven | org.xwiki.platform:xwiki-platform-mentions-ui | ≥ 14.0&&< 14.4 | 14.4org.xwiki.platform:xwiki-platform-mentions-ui:14.4 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.xwiki.platform:xwiki-platform-mentions-ui, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.xwiki.platform:xwiki-platform-mentions-ui to 13.10.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-c5v8-2q4r-5w9v is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-c5v8-2q4r-5w9v can be triaged on real exposure rather than presence alone.
Tailored to GHSA-c5v8-2q4r-5w9v. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-c5v8-2q4r-5w9v in your dependencies?
O3 Security finds GHSA-c5v8-2q4r-5w9v across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.