Vulnerability in Quinn-Rs Quinn

CVE-2026-31812

Quinn is a pure-Rust, async-compatible implementation of the IETF QUIC transport protocol. Prior to 0.11.14, a remote, unauthenticated attacker can trigger a denial of service in applications using vulnerable quinn versions by sending a crafted QUIC Initial packet containing malformed quic_transport_parameters. In quinn-proto parsing logic, attacker-controlled varints are decoded with unwrap(), so truncated encodings cause Err(UnexpectedEnd) and panic. This is reachable over the network with a single packet and no prior trust or authentication. This vulnerability is fixed in 0.11.14.

EPSS: 0.005 (41.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-31812?
CVE-2026-31812 is a medium-severity vulnerability in Quinn-Rs Quinn, classified under CWE-248. CVSS score: 5.3/10. Published 2026-03-10.
How severe is CVE-2026-31812?
Medium severity. CVSS v3 base score is 5.3 out of 10.