{"id":"CVE-2026-77401","aliases":["GHSA-pq59-9fq7-m886"],"url":"https://o3.security/vulnerability/CVE-2026-77401","summary":"Zope AccessControl: Information disclosure through Python string `format` and `format_map` functions","details":"Zope AccessControl provides a general security framework for use in Zope. Prior to 7.4, applications that allow untrusted users to create and execute AccessControl-controlled Python code do not safely guard str.format and str.format_map when those methods are reached through a str subclass. In both ImplPython.py and cAccessControl.c, Python formatting can recursively access attributes and subscriptions using unrestricted getattr and getitem behavior instead of the policy-restricted getattr and getitem operations. A controlled format string can therefore disclose objects reachable from values available to the formatting operation. This issue is fixed in version 7.4.","published":"2026-09-16T14:28:01.186Z","modified":"2026-09-18T08:11:08.577091Z","cvss":{"score":6.8,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"PyPI","name":"accesscontrol","fixedVersion":"7.4"}],"fix":{"url":"https://github.com/zopefoundation/AccessControl/commit/f980450eea416718be62847f34dfd51822938e43","label":"zopefoundation/AccessControl@f980450"},"references":[{"type":"WEB","url":"https://github.com/zopefoundation/AccessControl/releases/tag/7.4"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77401.json"},{"type":"ADVISORY","url":"https://github.com/zopefoundation/AccessControl/security/advisories/GHSA-pq59-9fq7-m886"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-77401"},{"type":"FIX","url":"https://github.com/zopefoundation/AccessControl/commit/f980450eea416718be62847f34dfd51822938e43"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-18T08:11:08.577091Z"}}