GHSA-3wxg-w96j-8hq9 is a low-severity (CVSS 3.7) CWE-80 vulnerability in craftcms/cms. 1 public exploit reference exists, so weaponization risk is real. A fix is available for craftcms/cms — see the affected versions and patch details below.
CraftCMS stored XSS in Quick Post widget error message
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.
Exploitation and automatability from CISA’s SSVC triage for GHSA-3wxg-w96j-8hq9.
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-3wxg-w96j-8hq9 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
craftcms/cms🐘craftcms/cmsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The platform does not filter input and encode output in Quick Post validation error message, which can deliver an XSS payload.
Details
Old CVE fixed the XSS in label HTML but didn’t fix it when clicking save.
PoC
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Login at admin
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Go to setting
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Create a Section
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On Entry page, click Edit label
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Inject the XSS payload into the label and save
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On the admin dashboard choose new widget -> Quick Post
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In Quick Post, click save with blank slug; The XSS will be executed
"errors":{"title":["<script>alert('nono')</script> cannot be blank."],"slug":["Slug cannot be blank."]
Fixed in https://github.com/craftcms/cms/commit/9d0cd0bda7c8a830a3373f8c0f06943e519ac888
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | craftcms/cms | ≥ 4.0.0-RC1&&< 4.4.6 | 4.4.6composer require craftcms/cms:^4.4.6 |
| 🐘Packagist | craftcms/cms | ≥ 3.0.0&&< 3.8.6 | 3.8.6composer require craftcms/cms:^3.8.6 |
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 craftcms/cms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update craftcms/cms to 4.4.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3wxg-w96j-8hq9 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-3wxg-w96j-8hq9 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-3wxg-w96j-8hq9. 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-3wxg-w96j-8hq9 in your dependencies?
O3 Security finds GHSA-3wxg-w96j-8hq9 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.