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CVE-2026-44435highCWE-400CWE-617

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

21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 7.5epss 0.3%
exploitation probability
0.3%top 80% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
h2o · quicly