CVE-2026-61544: libp2p rust-libp2p Uncaught Exception

Vulnerability summary

CVE-2026-61544 is a high (CVSS 8.2) Uncaught Exception vulnerability in libp2p rust-libp2p. EPSS estimates a 0.28% chance of exploitation in the next 30 days, higher than 19.6% of scored vulnerabilities.

Timeline

1. 15-09-2026
   PublishedVulnerability first disclosed.
2. 17-09-2026
   Last modifiedVulnerability information updated.

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.

• CWE-248Uncaught ExceptionAn exception is thrown from a function, but it is not caught.