CVE-2026-44435

highCVSS 7.5covered by 1 sourcefirst seen 2026-07-16

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.

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Exploitation outlook

Low exploitation risk0.28% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 20% of all EPSS-scored CVEs.

Advisory coverage (1)

highCVE-2026-44435: Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP …nvd · 2026-07-16

External references

NVD record for CVE-2026-44435

CVE.org record

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