{"id":"CVE-2026-126081","summary":"Action Pack: Possible Strong Parameters bypass in Parameters#each_key","details":"Action Pack is a framework for handling and responding to web requests. Prior to 8.1.4.1 and 8.0.5.2, ActionController::Parameters#each_key delegates to the internal ActiveSupport::HashWithIndifferentAccess that holds the request parameters, so when called with a block it returns that hash instead of the Parameters instance. The hash does not respond to permitted?, so Active Model mass assignment (new, assign_attributes, update) accepts it without raising ActiveModel::ForbiddenAttributesError. An application that passes the return value of each_key to mass assignment could allow a remote, unauthenticated attacker to set attributes that the application does not permit, such as an authorization flag. This is an incomplete fix of CVE-2020-8164, which made each, each_pair and each_value return the Parameters instance but left each_key delegated. An application is affected if it passes the return value of ActionController::Parameters#each_key, called with a block, to mass assignment. Rails itself makes no such call. This issue is fixed in versions 8.1.4.1 and 8.0.5.2.","aliases":["GHSA-wm3x-v3qw-4jh3"],"modified":"2026-11-11T10:47:26.585176644Z","published":"2026-11-10T21:06:31.425Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126081.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-915"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126081.json"},{"type":"FIX","url":"https://github.com/rails/rails/commit/2fc8838300133931e19eed3ea6cee76a7e83f19c"},{"type":"FIX","url":"https://github.com/rails/rails/commit/8ba746e0a786458c281060823f2ccc5c5f6312ac"},{"type":"WEB","url":"https://github.com/rails/rails/releases/tag/v8.0.5.2"},{"type":"WEB","url":"https://github.com/rails/rails/releases/tag/v8.1.4.1"},{"type":"ADVISORY","url":"https://github.com/rails/rails/security/advisories/GHSA-wm3x-v3qw-4jh3"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-126081"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/rails/rails","events":[{"introduced":"1cdd190a25e483b65f1f25bbd0f13a25d696b461"},{"fixed":"3f290b759c8e2ffe7c257951b1255740751355e4"},{"introduced":"0"},{"fixed":"235c597b100321b6bd2d62f8df63707f42b25b2d"},{"fixed":"2fc8838300133931e19eed3ea6cee76a7e83f19c"},{"fixed":"8ba746e0a786458c281060823f2ccc5c5f6312ac"}],"database_specific":{"extracted_events":[{"source":"AFFECTED_FIELD","strategy":"StringRangeExpression","range":[{"introduced":"8.1"},{"fixed":"8.1.4.1"}]},{"strategy":"StringRangeExpression","range":[{"introduced":"0"},{"fixed":"8.0.5.2"}],"source":"AFFECTED_FIELD"},{"range":[{"fixed":"2fc8838300133931e19eed3ea6cee76a7e83f19c"}],"source":"REFERENCES_COMMIT"},{"range":[{"fixed":"8ba746e0a786458c281060823f2ccc5c5f6312ac"}],"source":"REFERENCES_COMMIT"},{"original_tag":"v8.0.5.2","range":[{"fixed":"235c597b100321b6bd2d62f8df63707f42b25b2d"}],"source":"REFERENCES_TAG"},{"source":"REFERENCES_TAG","original_tag":"v8.1.4.1","range":[{"fixed":"3f290b759c8e2ffe7c257951b1255740751355e4"}]}]}}],"versions":["v8.0.5.1","v8.1.4","v8.0.5","v8.1.3","v8.0.4","v8.1.2","v8.1.1","v8.1.0","v8.0.3","v8.0.2","v8.0.1","v8.0.0","v8.0.0.rc2","v8.0.0.rc1","v8.0.0.beta1","v7.1.0.beta1","v7.0.0.alpha2","v7.0.0.alpha1","v6.1.0.rc1","v6.0.0.beta2","v6.0.0.beta1","v5.1.0.beta1","v5.0.0.beta4","v5.0.0.beta2","v5.0.0.beta1","v4.2.0.beta1","v4.0.0.rc1","v4.0.0.beta1","v3.2.0.rc1","v3.1.0.rc1","v3.1.0.beta1","v3.0.0.beta3","v3.0.0.beta.3","v2.0.1","v2.0.0","v2.0.0_RC2","v2.0.0_RC1","v2.0.0_PR","v1.1.1","v1.1.0","v1.1.0_RC1","v0.14.3","v0.14.1","v0.13.1","v0.13.0","v0.12.0","v0.11.1","v0.11.0","v0.10.1","v0.10.0","v0.9.5","v0.9.4.1","v0.9.4","v0.9.3","v0.9.2","v0.9.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-126081.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}