How severe is GHSA-mh64-ph39-mrc9?

GHSA-mh64-ph39-mrc9 has a CVSS score of 5.6/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-mh64-ph39-mrc9?

GHSA-mh64-ph39-mrc9 affects the following packages: quiche (crates.io). Ecosystems affected: crates.io.

How do I fix GHSA-mh64-ph39-mrc9?

Update quiche to 0.29.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mh64-ph39-mrc9 is resolved across your whole dependency graph.

How do I detect GHSA-mh64-ph39-mrc9 in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for quiche. 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-mh64-ph39-mrc9 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-mh64-ph39-mrc9?

O3 pinpoints whether GHSA-mh64-ph39-mrc9 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-mh64-ph39-mrc9 actively exploited in the wild?

No public exploit code has been indexed for GHSA-mh64-ph39-mrc9 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 type of vulnerability is GHSA-mh64-ph39-mrc9?

GHSA-mh64-ph39-mrc9 is classified as Use After Free (CWE-416). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-mh64-ph39-mrc9 published, and has it been updated?

GHSA-mh64-ph39-mrc9 was published on June 19, 2026 and was last updated on June 19, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🦀 crates.io

GHSA-mh64-ph39-mrc9

MEDIUM

GHSA-mh64-ph39-mrc9 is a medium-severity (CVSS 5.6) Use After Free vulnerability in quiche. O3 Security confirms whether GHSA-mh64-ph39-mrc9 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Cloudflare Quiche: Use-after-free in connection ID iterator FFI functions

Also known asCVE-2026-11941

Published

Jun 19, 2026

Updated

Jun 19, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Blast Radius

1 pkg affected

🦀quiche

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

Description

Impact

Cloudflare Quiche was affected by 2 use-after-free vulnerabilities in the connection ID iterator FFI functions.

The quiche_connection_id_iter_next and quiche_conn_retired_scid_next functions would return a pointer to a ConnectionId to the applications via function arguments, but the the owned ConnectionId would be dropped at the end of those functions' scope.

Only applications using those FFI functions are affected. The FFI API is disabled by default by a build-time feature flag.

quiche 0.29.2 is the earliest version containing the fix for this issue.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`quiche`	≥ 0.20.0&&< 0.29.2	0.29.2

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for quiche. 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 quiche to 0.29.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mh64-ph39-mrc9 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-mh64-ph39-mrc9 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-mh64-ph39-mrc9. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact Cloudflare Quiche was affected by 2 use-after-free vulnerabilities in the connection ID iterator FFI functions. The `quiche_connection_id_iter_next` and `quiche_conn_retired_scid_next` functions would return a pointer to a `ConnectionId` to the applications via function arguments, but the the owned `ConnectionId` would be dropped at the end of those functions' scope. Only applications using those FFI functions are affected. The FFI API is disabled by default by a build-time feature flag. quiche 0.29.2 is the earliest version containing the fix for this issue.

O3 Security · Impact-Aware SCA

Is GHSA-mh64-ph39-mrc9 in your dependencies?

O3 detects GHSA-mh64-ph39-mrc9 across crates.io 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