PatchSiren cyber security CVE debrief
CVE-2026-31812 quinn-rs CVE debrief
CVE-2026-31812 is a denial of service vulnerability in Quinn, a pure-Rust, async-compatible implementation of the IETF QUIC transport protocol. A remote, unauthenticated attacker can trigger this vulnerability by sending a crafted QUIC Initial packet containing malformed quic_transport_parameters. The vulnerability is caused by the quinn-proto parsing logic decoding attacker-controlled varints with unwrap(), which causes Err(UnexpectedEnd) and panic when encountering truncated encodings. This vulnerability can be exploited over the network with a single packet and no prior trust or authentication. The vulnerability is fixed in Quinn version 0.11.14.
- Vendor
- quinn-rs
- Product
- quinn
- CVSS
- HIGH 8.7
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-03-10
- Original CVE updated
- 2026-08-25
- Advisory published
- 2026-03-10
- Advisory updated
- 2026-08-25
Who should care
Organizations using Quinn versions prior to 0.11.14 should be aware of this vulnerability and take steps to mitigate it. This includes updating to version 0.11.14 or later, and monitoring for potential attacks. Additionally, defenders should review their inventory of affected systems and prioritize patching.
Technical summary
CVE-2026-31812 is a denial of service vulnerability in Quinn, a pure-Rust, async-compatible implementation of the IETF QUIC transport protocol. The vulnerability is caused by the quinn-proto parsing logic decoding attacker-controlled varints with unwrap(), which causes Err(UnexpectedEnd) and panic when encountering truncated encodings. This can be exploited by a remote, unauthenticated attacker sending a crafted QUIC Initial packet. The vulnerability has a CVSS score of 8.7 and is considered HIGH severity. The vulnerability is fixed in Quinn version 0.11.14.
Defensive priority
High priority should be given to patching Quinn versions prior to 0.11.14. Defenders should review their inventory of affected systems and prioritize patching. Additionally, monitoring for potential attacks should be implemented.
Recommended defensive actions
- Update Quinn to version 0.11.14 or later
- Review inventory of affected systems and prioritize patching
- Monitor for potential attacks
- Implement compensating controls to detect and prevent exploitation
- Track exceptions and anomalies in system logs
Evidence notes
The CVE record and NVD detail provide information on the vulnerability, including its description, CVSS score, and affected versions. The source item URL provides additional information on the vulnerability, including references to related errata and bugzilla entries.
Sources and references
Verified primary and authoritative sources
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CVE-2026-31812 CVE Program record
Publisher, destination, and source semantics verified
URL: https://www.cve.org/CVERecord?id=CVE-2026-31812
CVE Program - Official CVE Program record with source-provided CVE metadata.
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CVE-2026-31812 NVD vulnerability detail
Publisher, destination, and source semantics verified
URL: https://nvd.nist.gov/vuln/detail/CVE-2026-31812
NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.
Supplemental references
-
Source reference
Unverified legacy reference
URL: https://github.com/quinn-rs/quinn/security/advisories/GHSA-6xvm-j4wr-6v98
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Source reference
Unverified legacy reference
URL: https://access.redhat.com/errata/RHSA-2026:13545
0b0ca135-0b70-47e7-9f44-1890c2a1c46c
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Source reference
Unverified legacy reference
URL: https://access.redhat.com/errata/RHSA-2026:19712
0b0ca135-0b70-47e7-9f44-1890c2a1c46c
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Source reference
Unverified legacy reference
URL: https://access.redhat.com/errata/RHSA-2026:22862
0b0ca135-0b70-47e7-9f44-1890c2a1c46c
-
Source reference
Unverified legacy reference
URL: https://access.redhat.com/errata/RHSA-2026:5459
0b0ca135-0b70-47e7-9f44-1890c2a1c46c
-
Source reference
Unverified legacy reference
URL: https://access.redhat.com/security/cve/CVE-2026-31812
0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Methodology and review provenance
AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.