CVE-2026-44435

high

Description

Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 937d0e9, an assertion failure is raised when the total number of valid handshake messages received over a CRYPTO stream of a single packet number space exceeds 32KB, causing a Denial of Service. This issue has been fixed by commit 937d0e9.

References

https://github.com/h2o/quicly/security/advisories/GHSA-2cw9-5673-73gv

https://github.com/h2o/quicly/commit/937d0e9e7c669fc2bee4920632ab6aaac60e4d81

Details

Source: Mitre, NVD

Published: 2026-07-16

Updated: 2026-07-16

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High

EPSS

EPSS: 0.00052