How severe is GHSA-4f6x-49g2-99fm?

GHSA-4f6x-49g2-99fm has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-4f6x-49g2-99fm?

GHSA-4f6x-49g2-99fm affects the following packages: mermaid (npm). Ecosystems affected: npm.

How do I fix GHSA-4f6x-49g2-99fm?

Update mermaid to 8.11.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4f6x-49g2-99fm is resolved across your whole dependency graph.

How do I detect GHSA-4f6x-49g2-99fm in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mermaid. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-4f6x-49g2-99fm if there is no patch (or I can't update yet)?

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 does O3 Security protect against GHSA-4f6x-49g2-99fm?

O3 pinpoints whether GHSA-4f6x-49g2-99fm is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-4f6x-49g2-99fm actively exploited in the wild?

No public exploit code has been indexed for GHSA-4f6x-49g2-99fm yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-4f6x-49g2-99fm?

GHSA-4f6x-49g2-99fm has an EPSS (Exploit Prediction Scoring System) score of 1.0%, placing it in the 59th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was GHSA-4f6x-49g2-99fm published, and has it been updated?

GHSA-4f6x-49g2-99fm was published on December 10, 2021 and was last updated on November 8, 2023. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

GHSA-4f6x-49g2-99fm: Cross-site Scripting in Mermaid (Medium 6.…

EPSS Exploitation Probability

via FIRST.org ↗

1.0%probability of exploitation in next 30 days

Lower Risk59th percentile+0.71%

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.

Blast Radius

1 pkg affected

Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.

mermaidnpm

9.6Mdownloads / week

Description

Mermaid before 8.11.0 allows XSS when the antiscript feature is used.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`mermaid`	all versions	8.11.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mermaid. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update mermaid to 8.11.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4f6x-49g2-99fm 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 pinpoints whether GHSA-4f6x-49g2-99fm is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-4f6x-49g2-99fm. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Mermaid before 8.11.0 allows XSS when the antiscript feature is used.

O3 Security · Impact-Aware SCA

Is GHSA-4f6x-49g2-99fm in your dependencies?

O3 detects GHSA-4f6x-49g2-99fm across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

GHSA-4f6x-49g2-99fm