CVE-2026-86250
Dashboard / Vulnerabilities / CVE-2026-86250
Summary: h3 before 2.0.1-rc.18 Denial of Service via Unbounded Chunked Cookie
Details: 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.
References: https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86250.json, https://github.com/h3js/h3/security/advisories/GHSA-q5pr-72pq-83v3, https://nvd.nist.gov/vuln/detail/CVE-2026-86250, https://www.vulncheck.com/advisories/h3-before-2.0.1-rc.18-denial-of-service-via-unbounded-chunked-cookie
Affected packages
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Affected ranges
Type: GIT
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