{"id":"CVE-2026-97689","title":"urllib3 is an HTTP client library for Python","summary":"urllib3 is an HTTP client library for Python. From 1.10.3 until 2.8.0, the HTTPResponse.read_chunked and HTTPResponse.stream methods can allocate unbounded memory because the streaming chunk parser buffers the chunk-size field until newl…","severity":"high","cvss":8.9,"cvssVector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H","cwe":["CWE-770"],"vendor":"urllib3","product":"urllib3","affected":["urllib3 >= 1.10.3, < 2.8.0"],"published":"2026-09-29","updated":"2026-09-29","sourceUpdated":"2026-09-29T17:17:16.493","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97689","references":[{"url":"https://github.com/urllib3/urllib3/commit/cd770b059b543be29298ea5c52afb0b1b090f5ed","label":"security-advisories@github.com"},{"url":"https://github.com/urllib3/urllib3/releases/tag/2.8.0","label":"security-advisories@github.com"},{"url":"https://github.com/urllib3/urllib3/security/advisories/GHSA-vxq7-64xx-v4gw","label":"security-advisories@github.com"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-29T16:21:49.840583Z"},"cvssSource":"cna","ingestedAt":"2026-09-29T16:39:33.273Z","slug":"CVE-2026-97689","body":"## Overview\n\nurllib3 is an HTTP client library for Python. From 1.10.3 until 2.8.0, the HTTPResponse.read_chunked and HTTPResponse.stream methods can allocate unbounded memory because the streaming chunk parser buffers the chunk-size field until newline or EOF without a length bound. The trigger is that a malicious server returns Transfer-Encoding: chunked followed by a very long run of bytes without a newline. The attack mechanism is that a malicious HTTP server sends a very long unterminated chunk-size line. The impact is that unbounded memory allocation can exhaust the client process. This issue is fixed in version 2.8.0.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":49,"depthScoreParts":{"impact":49,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}