{"id":"GHSA-fg72-q65g-wm5w","title":"Duplicate Advisory: H3: Unbounded Chunked Cookie Count in Session Cleanup Loop may Lead to Denial of Service","summary":"Duplicate Advisory: H3: Unbounded Chunked Cookie Count in Session Cleanup Loop may Lead to Denial of Service","severity":"high","cvss":7.5,"cwe":["CWE-400"],"vendor":"h3","product":"h3","ecosystem":"npm","affected":["h3 >= 2.0.0-beta.4, < 2.0.1-rc.18"],"published":"2026-09-06","updated":"2026-09-30","sourceUpdated":"2026-09-30T23:46:36Z","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-fg72-q65g-wm5w","references":[{"url":"https://github.com/h3js/h3/security/advisories/GHSA-q5pr-72pq-83v3"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-86250"},{"url":"https://www.vulncheck.com/advisories/h3-before-2.0.1-rc.18-denial-of-service-via-unbounded-chunked-cookie"},{"url":"https://github.com/advisories/GHSA-fg72-q65g-wm5w"}],"tags":["ghsa","npm"],"ingestedAt":"2026-10-01T00:33:27.743Z","slug":"GHSA-fg72-q65g-wm5w","body":"## Overview\n\n## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-q5pr-72pq-83v3. This link is maintained to preserve external references.\n\n## Original Description\nh3 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.\n\n## Affected packages\n\n- `h3 >= 2.0.0-beta.4, < 2.0.1-rc.18`\n\n## Remediation\n\nRefer to the advisory for the patched release.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}