7.5

CVE-2026-44435

Quicly: Remote Denial of Service via assertion failure when CRYPTO stream handshake data exceeds 32KB

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
H2o ≫ Quicly Version < 2026-05-29
VulnDex Vulnerability Enrichment
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EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.28% 0.198
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
security-advisories@github.com 7.5 3.9 3.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-400 Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

CWE-617 Reachable Assertion

The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.

https://github.com/h2o/quicly/security/advisories/GHSA-2cw9-5673-73gv
Vendor Advisory
https://github.com/h2o/quicly/commit/937d0e9e7c669fc2bee4920632ab6aaac60e4d81
Patch