How severe is CVE-2026-61544?

No CVSS score has been assigned to CVE-2026-61544 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-61544?

CVE-2026-61544 affects the following packages: libp2p-quic (crates.io). Ecosystems affected: crates.io.

How do I fix CVE-2026-61544?

Update libp2p-quic to 0.13.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-61544 is resolved across your whole dependency graph.

How do I detect CVE-2026-61544 in my crates.io dependencies?

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.

How do I mitigate CVE-2026-61544 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 CVE-2026-61544?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-61544 can be triaged on real exposure rather than presence alone.

Is CVE-2026-61544 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-61544 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 CVE-2026-61544?

CVE-2026-61544 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 14th 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.

What type of vulnerability is CVE-2026-61544?

CVE-2026-61544 is classified as CWE-248 (CWE-248). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-61544 published, and has it been updated?

CVE-2026-61544 was published on September 15, 2026 and was last updated on September 18, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-61544: libp2p-quic

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 CVE-2026-61544.

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

libp2p-rust is the official Rust language implementation of the libp2p networking stack. Prior to 0.13.1, libp2p-quic could panic during an inbound QUIC handshake when a remote peer presented a valid short-lived libp2p TLS certificate and delayed the final TLS 1.3 handshake fragment until after the certificate expired. In the Quinn post-handshake upgrade path, transports/quic/src/connection/connecting.rs called libp2p_tls::certificate::parse a second time in remote_peer_id and used expect on the result. The repeated wall-clock validity check could reject the now-expired certificate, causing the expect call to terminate any application exposing an affected libp2p-quic listener. This vulnerability is fixed in 0.13.1.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`libp2p-quic`	all versions	0.13.1`cargo update -p libp2p-quic --precise 0.13.1`

Detection & mitigation playbook

Open-source dependency

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.
Fix
Update libp2p-quic to 0.13.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-61544 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 CVE-2026-61544 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2026-61544. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

libp2p-rust is the official Rust language implementation of the libp2p networking stack. Prior to 0.13.1, libp2p-quic could panic during an inbound QUIC handshake when a remote peer presented a valid short-lived libp2p TLS certificate and delayed the final TLS 1.3 handshake fragment until after the certificate expired. In the Quinn post-handshake upgrade path, transports/quic/src/connection/connecting.rs called libp2p_tls::certificate::parse a second time in remote_peer_id and used expect on the result. The repeated wall-clock validity check could reject the now-expired certificate, causing th

O3 Security · Impact-Aware SCA

Is CVE-2026-61544 in your dependencies?

O3 Security finds CVE-2026-61544 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works

CVE-2026-61544 — libp2p-quic