CVE-2026-31812: Quinn quinn-proto denial of service via malformed QUIC packet

CVE-2026-31812 · Severity: medium · CVSS 5.3 · Published 2026-03-10

Quinn is a software library used by applications to communicate using the QUIC internet protocol. A remote attacker can send a single specially crafted data packet to a server using this library, causing the application to crash immediately. This results in a denial of service, potentially disrupting business operations and service availability for customers without requiring any login credentials.

Technologies: quinn-proto (crates.io), Quinn-Rs Quinn-Proto. Vendors: crates.io, Quinn-Rs.

Quick answers

Is CVE-2026-31812 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-31812 being exploited in the wild.
How severe is CVE-2026-31812?
Medium severity, with a CVSS score of 5.3, published 10 March 2026.
Which products and versions are affected?
quinn-proto (crates.io) SEMVER:introduced=0,fixed=0.11.14, SEMVER:introduced=0.5.0,fixed=0.11.14; Quinn-Rs Quinn-Proto < 0.11.14.
Is there a fix for CVE-2026-31812?
Yes. quinn-proto (crates.io): upgrade to 0.11.14 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-31812 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-31812?
Check whether you run quinn-proto (crates.io) or Quinn-Rs Quinn-Proto at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • quinn-proto (crates.io): upgrade to 0.11.14 or later
    cargo update -p quinn-proto

Technical details

A denial of service vulnerability exists in quinn-proto due to an uncaught exception (panic) during the parsing of QUIC transport parameters. The root cause is the use of the `unwrap()` method on a fallible varint decoding operation; when a truncated or malformed varint is encountered, the decoder returns an `UnexpectedEnd` error, which triggers a thread panic. An unauthenticated remote attacker can exploit this by sending a single crafted QUIC Initial packet containing malformed `quic_transport_parameters`. The vulnerability is fixed in version 0.11.14 of the Quinn library.

Affected products

  • quinn-rs quinn-proto < 0.11.14
  • Red Hat Red Hat Ansible Automation Platform 2.6
  • Red Hat Red Hat OpenShift Container Platform 4
  • Red Hat Red Hat Enterprise Linux 9, 10

Identifiers

  • CVE-2026-31812
  • GHSA-6xvm-j4wr-6v98
  • RUSTSEC-2026-0037

Timeline

  • 2026-03-09: advisory: GitHub Security Advisory GHSA-6xvm-j4wr-6v98 published
  • 2026-03-10: disclosed: CVE-2026-31812 published to NVD
  • 2026-05-04: patched: Red Hat released security updates for Ansible Automation Platform

References

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