{"id":"CVE-2026-126072","aliases":["GHSA-rwvh-fw6r-pwvp"],"url":"https://o3.security/vulnerability/CVE-2026-126072","summary":"Action Pack: Possible DoS vulnerability in Action Controller Live streaming","details":"### Impact\n`ActionController::Live::Buffer#close` pushes its end-of-stream marker onto the response's bounded queue while it holds the buffer's monitor. When the client has stopped reading and the queue is full, the push blocks, and `Buffer#abort`, which runs when the client disconnects or a write times out, waits indefinitely for the same monitor. Each such response could permanently hold a web server thread and its `ActionController::Live` thread, possibly resulting in a DoS vulnerability through thread exhaustion.\n\nApplications that stream responses with `ActionController::Live`, including `send_stream`, are affected. Applications that serve large files through Active Storage proxy mode are exposed to unauthenticated clients.\n\n### Releases\nThe fixed releases are available at the normal locations.\n\nPatches for those who cannot upgrade at once:\n- 8.1: https://github.com/rails/rails/commit/ccbfc09690fef05fdd2a9969c917a71b92cc98fc.patch\n- 8.0: https://github.com/rails/rails/commit/27ad18ed5900dee28ba20e9c6fc718ff751fa215.patch\n\n### Credit\nThis issue was found by the Anthropic OSS Scanner (ANT-2026-LDFW5N2T).","published":"2026-11-10T20:44:52.734Z","modified":"2026-11-12T02:48:33.092113806Z","cvss":{"score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"RubyGems","name":"actionpack","fixedVersion":"8.1.4.1"},{"ecosystem":"RubyGems","name":"actionpack","fixedVersion":"8.0.5.2"}],"fix":{"url":"https://github.com/rails/rails/commit/27ad18ed5900dee28ba20e9c6fc718ff751fa215","label":"rails/rails@27ad18e"},"references":[{"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/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126072.json"},{"type":"ADVISORY","url":"https://github.com/rails/rails/security/advisories/GHSA-rwvh-fw6r-pwvp"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-126072"},{"type":"FIX","url":"https://github.com/rails/rails/commit/27ad18ed5900dee28ba20e9c6fc718ff751fa215"},{"type":"FIX","url":"https://github.com/rails/rails/commit/ccbfc09690fef05fdd2a9969c917a71b92cc98fc"},{"type":"PACKAGE","url":"https://github.com/rails/rails"},{"type":"WEB","url":"https://github.com/rubysec/ruby-advisory-db/blob/master/gems/actionpack/GHSA-rwvh-fw6r-pwvp.yml"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-11-12T02:48:33.092113806Z"}}