{"cve":"CVE-2026-3644","nvd":{"published":"2026-03-16T18:16:09.907","modified":"2026-08-13T01:16:53.120","status":"Modified","description":"The fix for CVE-2026-0672, which rejected control characters in http.cookies.Morsel, was incomplete. The Morsel.update(), |= operator, and unpickling paths were not patched, allowing control characters to bypass input validation. Additionally, BaseCookie.js_output() lacked the output validation applied to BaseCookie.output().","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N","score":6.0},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5},"cwes":["CWE-20","CWE-116"],"references":["https://github.com/python/cpython/commit/3974092b037f9a3b000fb15b48ea61ce3b25d330","https://github.com/python/cpython/commit/556aa098e738b127c714866f819b4abe2f7593d8","https://github.com/python/cpython/commit/57e88c1cf95e1481b94ae57abe1010469d47a6b4","https://github.com/python/cpython/commit/62ceb396fcbe69da1ded3702de586f4072b590dd","https://github.com/python/cpython/commit/d16ecc6c3626f0e2cc8f08c309c83934e8a979dd"],"products":["python:python"],"source":"nvd","synced_at":"2026-10-19T22:26:19.218427112+00:00"},"epss":{"cve":"CVE-2026-3644","score":0.00497,"percentile":0.42635,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}