{"id":"CVE-2026-126081","state":"PUBLISHED","title":"Action Pack: Possible Strong Parameters bypass in Parameters#each_key","description":"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.","publishedAt":"2026-11-10T21:06:31.425Z","updatedAt":"2026-11-10T21:06:31.425Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["rails rails"],"affected":[{"vendor":"rails","product":"rails","versions":[{"version":">= 8.1, < 8.1.4.1","status":"affected"},{"version":"< 8.0.5.2","status":"affected"}]}],"references":["https://github.com/rails/rails/security/advisories/GHSA-wm3x-v3qw-4jh3","https://github.com/rails/rails/commit/2fc8838300133931e19eed3ea6cee76a7e83f19c","https://github.com/rails/rails/commit/8ba746e0a786458c281060823f2ccc5c5f6312ac","https://github.com/rails/rails/releases/tag/v8.0.5.2","https://github.com/rails/rails/releases/tag/v8.1.4.1"],"weaknesses":["CWE-915"],"ingestedAt":"2026-11-10T21:16:04.848Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/126xxx/CVE-2026-126081.json","commit":"c5a01f083f4f1bb59d77be7743a509cc9f9b04ca","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-126081","state":"PUBLISHED","datePublished":"2026-11-10T21:06:31.425Z","dateUpdated":"2026-11-10T21:06:31.425Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-11-10T17:07:43.285Z"},"containers":{"cna":{"title":"Action Pack: Possible Strong Parameters bypass in Parameters#each_key","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"rails","product":"rails","versions":[{"version":">= 8.1, < 8.1.4.1","status":"affected"},{"version":"< 8.0.5.2","status":"affected"}]}],"references":[{"url":"https://github.com/rails/rails/security/advisories/GHSA-wm3x-v3qw-4jh3","name":"https://github.com/rails/rails/security/advisories/GHSA-wm3x-v3qw-4jh3","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/rails/rails/commit/2fc8838300133931e19eed3ea6cee76a7e83f19c","name":"https://github.com/rails/rails/commit/2fc8838300133931e19eed3ea6cee76a7e83f19c","tags":["x_refsource_MISC"]},{"url":"https://github.com/rails/rails/commit/8ba746e0a786458c281060823f2ccc5c5f6312ac","name":"https://github.com/rails/rails/commit/8ba746e0a786458c281060823f2ccc5c5f6312ac","tags":["x_refsource_MISC"]},{"url":"https://github.com/rails/rails/releases/tag/v8.0.5.2","name":"https://github.com/rails/rails/releases/tag/v8.0.5.2","tags":["x_refsource_MISC"]},{"url":"https://github.com/rails/rails/releases/tag/v8.1.4.1","name":"https://github.com/rails/rails/releases/tag/v8.1.4.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-915","lang":"en","description":"CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-11-10T21:06:31.425Z"},"source":{"advisory":"GHSA-wm3x-v3qw-4jh3","discovery":"UNKNOWN"}}}}}