Quicly assertion failures

published 2024-10-11 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-41457

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 48%
public exploits: 0; none known

Quicly is an IETF QUIC protocol implementation. Quicly up to commtit d720707 is susceptible to a denial-of-service attack. A remote attacker can exploit these bugs to trigger an assertion failure that crashes process using quicly. The vulnerability is addressed with commit 2a95896104901589c495bc41460262e64ffcad5c.

Patch / fix

fixed in 1 links 1

h2o_project quicly 2a95896104901589c495bc41460262e64ffcad5c

github.com/h2o/quicly@2a95896 commit

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 2 y ago (2024-10-11)

Exploit prediction

0.58% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

h2o quicly
h2o_project quicly

Classification

Weakness

CWE-617 Reachable Assertion

References

github.com /h2o/quicly/commit/2a95896104901589c495bc41460262e64ffcad5c
patch
github.com /h2o/quicly/security/advisories/GHSA-mp3c-h5gg-mm6p
vendor-advisory

Sources

CVE List CVE-2024-45396
NVD CVE-2024-45396

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary