Improper input validation in H2o Quicly
CVE-2025-61684
Quicly, an IETF QUIC protocol implementation, is susceptible to a denial-of-service attack prior to commit d9d3df6a8530a102b57d840e39b0311ce5c9e14e. A remote attacker can exploit these bugs to trigger an assertion failure that crashes proc…
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
EPSS: 0.003 (25.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- H2o Quicly — versions < d9d3df6
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2025-61684?
- CVE-2025-61684 is a high-severity vulnerability in H2o Quicly, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2026-01-19.
- How severe is CVE-2025-61684?
- High severity. CVSS v3 base score is 7.5 out of 10.