What’s Vulnerable › Vulnerabilities

CVE-2026-31812: Quinn affected by unauthenticated remote DoS via panic in QUIC transport parameter parsing

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-10 · updated 2026-08-25
• Weakness: CWE-248

Description

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.

Affected products

• quinn-rs quinn: before 0.11.14

References

• https://github.com/quinn-rs/quinn/security/advisories/GHSA-6xvm-j4wr-6v98
• https://access.redhat.com/errata/RHSA-2026:13545
• https://access.redhat.com/errata/RHSA-2026:19712
• https://access.redhat.com/errata/RHSA-2026:22862
• https://access.redhat.com/errata/RHSA-2026:5459
• https://access.redhat.com/security/cve/CVE-2026-31812
• https://bugzilla.redhat.com/show_bug.cgi?id=2446330
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31812.json

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