Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
🦀 crates.io
Not in CISA KEV

GHSA-5hq8-qhww-jm7q libp2p-quic

Fix: libp2p/rust-libp2p#6525

GHSA-5hq8-qhww-jm7q is a CWE-248 vulnerability in libp2p-quic. A fix is available for libp2p-quic — see the affected versions and patch details below.

libp2p-quic: Remote panic via certificate expiry race during QUIC handshake

Also known asCVE-2026-61544
Published
Sep 15, 2026
Updated
Sep 15, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 19, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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.
  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for GHSA-5hq8-qhww-jm7q.

EPSS Exploitation Probability

via FIRST.org ↗
0.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs14th percentile — riskier than 14% of all scored CVEsHighest risk

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.

Real-World Exposure

1 pkg affected
🦀libp2p-quic

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

Summary

libp2p-quic can panic on an inbound QUIC handshake if a malicious peer presents a valid, short lived libp2p TLS certificate and delays the final TLS 1.3 handshake fragment until the certificate expires.

This is remotely reachable by a network peer and can crash applications exposing a libp2p QUIC listener.

Details

During the TLS handshake, libp2p-tls parses and validates the peer certificate. After Quinn reports handshake completion, libp2p-quic re-parses the same certificate in the post-handshake upgrade path and assumes this cannot fail:

https://github.com/libp2p/rust-libp2p/blob/969b707bf1177ebebd1febc285c3fd22793b95c5/transports/quic/src/connection/connecting.rs#L65-L66

However, libp2p_tls::certificate::parse() re-runs certificate verification on every call, including a wall-clock validity check. A certificate that was valid during the first handshake time parse can expire before the second post-handshake parse, causing the expect(...) to panic.

PoC

A malicious peer can trigger this by:

  1. Opening a QUIC connection to a libp2p QUIC listener.
  2. Presenting a valid libp2p TLS certificate with a very short lifetime.
  3. Allowing the initial handshake-time certificate validation to succeed.
  4. Withholding the final client handshake fragment packet until after the certificate expires, but before the QUIC handshake timeout elapses.
  5. The listener completes the handshake and hits the post-handshake certificate re-parse, which panics.

Impact

Remote unauthenticated denial of service. Any application exposing an affected libp2p-quic listener can be crashed by a network peer that performs a valid-looking QUIC/TLS handshake with attacker-controlled timing. No malformed packets are required.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🦀crates.iolibp2p-quicall versions0.13.1cargo update -p libp2p-quic --precise 0.13.1

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for libp2p-quic, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update libp2p-quic to 0.13.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5hq8-qhww-jm7q is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-5hq8-qhww-jm7q can be triaged on real exposure rather than presence alone.

Tailored to GHSA-5hq8-qhww-jm7q. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary `libp2p-quic` can panic on an inbound QUIC handshake if a malicious peer presents a valid, short lived libp2p TLS certificate and delays the final TLS 1.3 handshake fragment until the certificate expires. This is remotely reachable by a network peer and can crash applications exposing a libp2p QUIC listener. ### Details During the TLS handshake, `libp2p-tls` parses and validates the peer certificate. After Quinn reports handshake completion, `libp2p-quic` re-parses the same certificate in the post-handshake upgrade path and assumes this cannot fail: https://github.com/libp2p/ru
O3 Security · Impact-Aware SCA

Is GHSA-5hq8-qhww-jm7q in your dependencies?

O3 Security finds GHSA-5hq8-qhww-jm7q across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-5hq8-qhww-jm7q: libp2p-quic DoS | O3 Security