How severe is GHSA-w4pr-4vjg-hffh?

GHSA-w4pr-4vjg-hffh has a CVSS score of 8.6/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-w4pr-4vjg-hffh?

GHSA-w4pr-4vjg-hffh affects the following packages: matrix-nio (PyPI). Ecosystems affected: PyPI.

How do I fix GHSA-w4pr-4vjg-hffh?

Update matrix-nio to 0.20 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w4pr-4vjg-hffh is resolved across your whole dependency graph.

How do I detect GHSA-w4pr-4vjg-hffh in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for matrix-nio. 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-w4pr-4vjg-hffh 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-w4pr-4vjg-hffh?

O3 pinpoints whether GHSA-w4pr-4vjg-hffh 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-w4pr-4vjg-hffh actively exploited in the wild?

No public exploit code has been indexed for GHSA-w4pr-4vjg-hffh 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-w4pr-4vjg-hffh?

GHSA-w4pr-4vjg-hffh has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 42th 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-w4pr-4vjg-hffh published, and has it been updated?

GHSA-w4pr-4vjg-hffh was published on September 30, 2022 and was last updated on February 20, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

GHSA-w4pr-4vjg-hffh: matrix-nio (High 8.6)

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk42th percentile+0.31%

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

🐍matrix-nio

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

When matrix-nio before 0.20 requests a room key from our devices, it correctly accepts key forwards only if they are a response to a previous request. However, it doesn't check that the device that responded matches the device the key was requested from.

This allows a malicious homeserver to insert room keys of questionable validity into the key store in some situations, potentially assisting in an impersonation attack.

For more information

If you have any questions or comments about this advisory, e-mail us at [email protected].

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`matrix-nio`	all versions	0.20

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for matrix-nio. 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 matrix-nio to 0.20 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w4pr-4vjg-hffh 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-w4pr-4vjg-hffh 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-w4pr-4vjg-hffh. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

When matrix-nio before 0.20 requests a room key from our devices, it correctly accepts key forwards only if they are a response to a previous request. However, it doesn't check that the device that responded matches the device the key was requested from. This allows a malicious homeserver to insert room keys of questionable validity into the key store in some situations, potentially assisting in an impersonation attack. ### For more information If you have any questions or comments about this advisory, e-mail us at [[email protected]](mailto:[email protected]).

O3 Security · Impact-Aware SCA

Is GHSA-w4pr-4vjg-hffh in your dependencies?

O3 detects GHSA-w4pr-4vjg-hffh across PyPI 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-w4pr-4vjg-hffh