CVE-2025-61684

Quicly has assertion failures

Published Jan 19, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
Quicly, an IETF QUIC protocol implementation, is susceptible to a denial-of-service attack prior to commit d9d3df6a8530a102b57d840e39b0311ce5c9e14e. A remote attacker can exploit these bugs to trigger an assertion failure that crashes process using Quicly. Commit d9d3df6a8530a102b57d840e39b0311ce5c9e14e fixes the issue.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared H2o
H2o quicly
Weaknesses CWE-617
CPEs cpe:2.3:a:h2o:quicly:*:*:*:*:*:*:*:*
Vendors & Products H2o
H2o quicly
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared H20
H20 quickly
Vendors & Products H20
H20 quickly
Type Values Removed Values Added
Description Quicly, an IETF QUIC protocol implementation, is susceptible to a denial-of-service attack prior to commit d9d3df6a8530a102b57d840e39b0311ce5c9e14e. A remote attacker can exploit these bugs to trigger an assertion failure that crashes process using Quicly. Commit d9d3df6a8530a102b57d840e39b0311ce5c9e14e fixes the issue.
Title Quicly has assertion failures
Weaknesses CWE-20
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jan 20, 2026, 3:49 PM
Reserved
Sep 29, 2025, 8:25 PM
Status
Analyzed
Published
Jan 19, 2026, 4:15 PM
Modified
Jun 17, 2026, 9:50 AM