Security Advisory
CVE-2026-86250
CVSS 7.5
HIGH
Vulnerability Description
h3 versions before 2.0.1-rc.18 fail to validate the chunk count parsed from user-controlled cookie values in setChunkedCookie() and deleteChunkedCookie() functions. Attackers can send a crafted cookie header with an extremely large chunk count to trigger an O(n²) cleanup loop that hangs the server process.
Published Date
2026-09-06T12:17:15.767
Data Feed
NIST National Vulnerability Database