{"id":"CVE-2026-82729","summary":"Quadratic chunk-size parsing in Mint.HTTP1.Parse allows CPU-exhaustion DoS","details":"Inefficient Algorithmic Complexity vulnerability in elixir-mint mint allows a remote HTTP server to exhaust CPU on the client host and cause a denial of service.\n\nparse_hex_prefix/2 in lib/mint/http1/parse.ex folds each hex digit of a chunked response's chunk-size field into an arbitrary-precision accumulator with acc * 16 + digit and imposes no limit on the digit count. Because the accumulator grows without bound, the multiplication is not constant time and one pass over N digits costs O(N squared). handle_data/2 prepends conn.buffer and re-parses from the start on every socket message, so a server that dribbles the digits out in small packets makes the client pay that cost repeatedly. A run of roughly 512,000 hex digits costs over ten seconds of CPU in a single pass, measured on stock defaults. The parser reaches this state after a valid status line and a complete, valid header section, so an intermediary inspecting only headers sees an ordinary 200 response.\n\nThis issue affects mint: from 1.9.3 before 1.10.0.","aliases":["EEF-CVE-2026-82729","GHSA-7p8w-j234-7qc8"],"modified":"2026-10-28T02:31:01.331744435Z","published":"2026-09-04T14:31:20.562Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/82xxx/CVE-2026-82729.json","cna_assigner":"EEF","cwe_ids":["CWE-407"]},"references":[{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-82729.html"},{"type":"WEB","url":"https://github.com"},{"type":"WEB","url":"https://osv.dev/vulnerability/EEF-CVE-2026-82729"},{"type":"WEB","url":"https://repo.hex.pm"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/82xxx/CVE-2026-82729.json"},{"type":"ADVISORY","url":"https://github.com/elixir-mint/mint/security/advisories/GHSA-7p8w-j234-7qc8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-82729"},{"type":"FIX","url":"https://github.com/elixir-mint/mint/commit/bd2a4e7513594997c140cfef9fe0e968712fb588"},{"type":"PACKAGE","url":"https://github.com/elixir-mint/mint"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/elixir-mint/mint","events":[{"introduced":"fc7d16538db7e40b56ed489f08683225cb0197fa"},{"fixed":"bd2a4e7513594997c140cfef9fe0e968712fb588"},{"introduced":"f0b72c0b2363c98d0a220019d108ac6141715428"},{"fixed":"75c8be1fada9983d6972418d162d55b6e62d507e"}],"database_specific":{"extracted_events":[{"strategy":"StandardRange","range":[{"introduced":"fc7d16538db7e40b56ed489f08683225cb0197fa"},{"fixed":"bd2a4e7513594997c140cfef9fe0e968712fb588"}],"source":"AFFECTED_FIELD"},{"source":"AFFECTED_FIELD","strategy":"StandardRange","range":[{"introduced":"1.9.3"},{"fixed":"1.10.0"}]},{"range":[{"fixed":"bd2a4e7513594997c140cfef9fe0e968712fb588"}],"source":"REFERENCES_COMMIT"}]}}],"versions":["v1.9.3"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-82729.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"}]}