{"id":"CVE-2026-34830","summary":"Rack: Rack::Sendfile regex injection via HTTP_X_ACCEL_MAPPING header allows arbitrary file reads through nginx","details":"Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Sendfile#map_accel_path interpolates the value of the X-Accel-Mapping request header directly into a regular expression when rewriting file paths for X-Accel-Redirect. Because the header value is not escaped, an attacker who can supply X-Accel-Mapping to the backend can inject regex metacharacters and control the generated X-Accel-Redirect response header. In deployments using Rack::Sendfile with x-accel-redirect, this can allow an attacker to cause nginx to serve unintended files from configured internal locations. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.","aliases":["GHSA-qv7j-4883-hwh7"],"modified":"2026-04-06T00:44:16.993306740Z","published":"2026-04-02T16:47:40.490Z","related":["CGA-5926-72ff-mp26"],"database_specific":{"cwe_ids":["CWE-625"],"cna_assigner":"GitHub_M","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34830.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34830.json"},{"type":"ADVISORY","url":"https://github.com/rack/rack/security/advisories/GHSA-qv7j-4883-hwh7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34830"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/rack/rack","events":[{"introduced":"0"},{"fixed":"f2af0c8f869193fa7bb7d20b619b3003418e1055"}],"database_specific":{"versions":[{"introduced":"0"},{"fixed":"2.2.23"}]}},{"type":"GIT","repo":"https://github.com/rack/rack","events":[{"introduced":"572a42a705b423ce98ef4e81435d4f60fb0ae53d"},{"fixed":"ae8431120e66e92d1885ab8ec0a553d9cad5ec13"}],"database_specific":{"versions":[{"introduced":"3.0.0.beta1"},{"fixed":"3.1.21"}]}},{"type":"GIT","repo":"https://github.com/rack/rack","events":[{"introduced":"b68251c03788ff39d4a4b25424df7360426e4afd"},{"fixed":"e1f22fdbe99afd2126b6fbf05bb12399359574b7"}],"database_specific":{"versions":[{"introduced":"3.2.0"},{"fixed":"3.2.6"}]}}],"versions":["0.1","0.2","0.3","0.4","0.9","0.9.1","1.0","1.0.1","1.1","1.1.2","1.1.3","1.1.4","1.1.5","1.1.6","1.2","1.2.1","1.2.2","1.2.3","1.2.4","1.2.5","1.2.6","1.2.7","1.2.8","1.3.0","1.3.0.beta","1.3.0.beta2","1.3.1","1.3.10","1.3.2","1.3.3","1.3.4","1.3.5","1.3.6","1.3.7","1.3.8","1.3.9","1.4.0","1.4.1","1.4.2","1.4.3","1.4.4","1.4.5","1.4.6","1.4.7","1.5.0","1.5.1","1.5.2","1.5.3","1.5.4","1.5.5","1.6.0","1.6.0.beta","1.6.0.beta2","1.6.1","1.6.10","1.6.11","1.6.12","1.6.13","1.6.2","1.6.3","1.6.4","1.6.5","1.6.6","1.6.7","1.6.8","1.6.9","2.0.0","2.0.0.alpha","2.0.0.rc1","2.0.1","2.0.2","2.0.3","2.0.4","2.0.5","2.0.6","2.0.7","2.0.8","2.0.9","2.0.9.1","2.1.0","2.1.1","2.1.2","2.1.3","2.1.4","2.1.4.1","2.2.0","2.2.3","2.2.3.1","2.2.4","3.0.0","3.0.0.beta1","3.0.0.rc1","test","v2.0.9.2","v2.0.9.3","v2.0.9.4","v2.1.4.2","v2.1.4.3","v2.1.4.4","v2.2.1","v2.2.10","v2.2.11","v2.2.12","v2.2.13","v2.2.14","v2.2.15","v2.2.16","v2.2.17","v2.2.18","v2.2.19","v2.2.2","v2.2.20","v2.2.21","v2.2.22","v2.2.5","v2.2.6","v2.2.6.1","v2.2.6.2","v2.2.6.3","v2.2.6.4","v2.2.7","v2.2.8","v2.2.8.1","v2.2.9","v3.0.1","v3.0.10","v3.0.12","v3.0.13","v3.0.14","v3.0.15","v3.0.16","v3.0.17","v3.0.18","v3.0.2","v3.0.3","v3.0.4","v3.0.4.1","v3.0.4.2","v3.0.5","v3.0.6","v3.0.6.1","v3.0.7","v3.0.8","v3.0.9","v3.0.9.1","v3.1.0","v3.1.1","v3.1.10","v3.1.11","v3.1.12","v3.1.13","v3.1.14","v3.1.15","v3.1.16","v3.1.17","v3.1.18","v3.1.19","v3.1.2","v3.1.20","v3.1.21","v3.1.3","v3.1.4","v3.1.5","v3.1.6","v3.1.7","v3.1.8","v3.1.9","v3.2.0","v3.2.1","v3.2.2","v3.2.3","v3.2.4","v3.2.5","v3.2.6"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-34830.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"}]}