{"id":"CVE-2026-54659","aliases":["EUVD-2026-50088","GHSA-2xmw-f8j8-wfxc","UBUNTU-CVE-2026-54659"],"status":"published","title":"Pagy I18n locale option is not validated before being used in a file path","description":"Pagy is agnostic pagination in plain Ruby. From 43.0.0 until 43.5.6, Pagy::I18n.locale= in gem/lib/pagy/modules/i18n/i18n.rb stored locale values verbatim and later used them as \u003clocale\u003e.yml path components, allowing untrusted params[:locale] values with absolute paths or ../ sequences to create a file existence and readability oracle for YAML files. This issue is fixed in version 43.5.6.","severity":{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00369,"percentile":0.31018,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-200","CWE-22"],"published":"2026-07-28T22:25:29Z","modified":"2026-10-28T02:31:12Z","fixes":[{"ecosystem":"RubyGems","package":"pagy","fixed_in":["43.5.6"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"RubyGems","package":"pagy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"43.0.0"},{"fixed":"43.5.6"}]}]},{"source":"osv","ecosystem":"RubyGems","package":"pagy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"43.0.0"},{"fixed":"43.5.6"}]}],"versions":["43.0.0","43.0.1","43.0.2","43.0.3","43.0.4","43.0.5","43.0.6","43.0.7","43.1.0","43.1.1","43.1.2","43.1.3","43.1.4","43.1.5","43.1.6","43.1.7","43.1.8","43.2.0","43.2.1","43.2.10","43.2.2","43.2.3","43.2.4","43.2.5","43.2.6","43.2.7","43.2.8","43.2.9","43.3.0","43.3.1","43.3.2","43.3.3","43.4.0","43.4.1","43.4.2","43.4.3","43.4.4","43.5.0","43.5.1","43.5.2","43.5.3","43.5.4","43.5.5"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"ruby-pagy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["43.5.6-2","43.6.1-1"]}],"products":[{"vendor":"ddnexus","product":"pagy"}],"references":[{"url":"https://github.com/ddnexus/pagy/security/advisories/GHSA-2xmw-f8j8-wfxc","tags":["x_refsource_CONFIRM","exploit","advisory","web","report"]},{"url":"https://github.com/ddnexus/pagy/pull/908","tags":["x_refsource_MISC","fix","web","report"]},{"url":"https://github.com/ddnexus/pagy/commit/efcf09690e9fa7d7abdfb987b785a55f87e287df","tags":["x_refsource_MISC","fix","web","report"]},{"url":"https://github.com/ddnexus/pagy/releases/tag/43.5.6","tags":["x_refsource_MISC","web","report"]},{"url":"https://github.com/advisories/GHSA-2xmw-f8j8-wfxc"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54659.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54659","tags":["advisory"]},{"url":"https://github.com/ddnexus/pagy","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2026-54659","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-54659","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-54659","title":"Pagy I18n locale option is not validated before being used in a file path","description":"Pagy is agnostic pagination in plain Ruby. From 43.0.0 until 43.5.6, Pagy::I18n.locale= in gem/lib/pagy/modules/i18n/i18n.rb stored locale values verbatim and later used them as \u003clocale\u003e.yml path components, allowing untrusted params[:locale] values with absolute paths or ../ sequences to create a file existence and readability oracle for YAML files. This issue is fixed in version 43.5.6.","status":"published","published":"2026-07-28T22:25:35.231Z","modified":"2026-07-29T13:06:59.87Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"}],"cwes":["CWE-22","CWE-200"],"updated_at":"2026-11-02T13:38:09.774038Z"}],"euvd":[{"id":"EUVD-2026-50088","description":"Pagy is agnostic pagination in plain Ruby. From 43.0.0 until 43.5.6, Pagy::I18n.locale= in gem/lib/pagy/modules/i18n/i18n.rb stored locale values verbatim and later used them as \u003clocale\u003e.yml path components, allowing untrusted params[:locale] values with absolute paths or ../ sequences to create a file existence and readability oracle for YAML files. This issue is fixed in version 43.5.6.","status":"published","published":"2026-07-28T22:25:35Z","modified":"2026-07-29T13:06:59Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T18:02:30.152277Z"}],"ghsa":[{"id":"GHSA-2xmw-f8j8-wfxc","title":"Pagy I18n locale option is not validated before being used in a file path","description":"### Summary\n\n`Pagy::I18n.locale=` did not validate its argument before using it as a\npath component to load the matching dictionary file (`\u003clocale\u003e.yml`). An\napplication that assigns untrusted input to the locale — e.g. the common\npattern `Pagy::I18n.locale = params[:locale]` — let that input influence\nwhich file Pagy attempted to load.\n\n### Details\n\nThe setter stored the value as-is, and the loader joined it into a path\nand read it:\n\n```ruby\n# gem/lib/pagy/modules/i18n/i18n.rb\ndef locale=(value)\n  Thread.current[:pagy_locale] = value.to_s\nend\n\n# ...later, when translating:\npath = pathnames.reverse.map { |p| p.join(\"#{locale}.yml\") }.find(\u0026:exist?)\ndictionary = YAML.load_file(path)[locale]\n```\n\nBecause the locale was used verbatim, a value such as an absolute path or\na `../`-style string redirected the lookup outside the locales directory.\nPagy's subsequent structural check (`dictionary['pagy']['p11n']`)\nprevents the file's contents from being returned, so this is **not** a\ndirect file read.\n\nFixed in 43.5.6 by constraining the locale to a BCP 47 shape before use:\n\n```ruby\nLOCALE_PATTERN = /\\A[a-zA-Z]{2,8}(-[a-zA-Z0-9]{1,8})*\\z/\n\ndef locale=(value)\n  Thread.current[:pagy_locale] = value.to_s[LOCALE_PATTERN]\nend\n```\n\nAny non-matching value (including `nil`) resolves to the default locale\nand never reaches the file lookup.\n\n### PoC\n\nIn an application that sets `Pagy::I18n.locale = params[:locale]`, the\nloader appends `.yml` and reads `\u003clocale\u003e.yml`, so the request param\ncontrols the target path. For example, pointing it at the app's\n`config/database.yml`:\n\n1. Send a request with `?locale=../../../config/database` (adjust the\n   number of `../` to reach the app root from the gem's `locales/`\n   directory).\n2. Pagy calls `YAML.load_file` on the resulting `…/config/database.yml`.\n3. The outcome differs by whether that `.yml` exists, is readable, parses\n   as YAML, and has Pagy's expected structure — an existing, readable\n   `config/database.yml` raises a different error than a non-existent\n   path (which silently falls back to the default locale). This yields a\n   file-existence / readability oracle for `.yml` paths, and the targeted\n   file is read into the process during the attempt.\n\n### Impact\n\nInformation disclosure (CWE-22 / CWE-200): a file-existence / readability\noracle for `.yml` paths on the host, plus a server-side read of\nattacker-chosen files into the process. The file contents are not\nreturned in the response.\n\nOnly applications that pass **unsanitized end-user input** into\n`Pagy::I18n.locale=` are affected. Applications that set the locale from\ntrusted values are not affected.\n\n**Patched:** pagy 43.5.6.\n**Workaround (if you cannot upgrade):** validate the locale before\nassigning it, e.g.\n`Pagy::I18n.locale = params[:locale].to_s[/\\A[a-zA-Z]{2,8}(-[a-zA-Z0-9]{1,8})*\\z/]`,\nor restrict it to your known set of locales.","status":"published","published":"2026-07-28T22:25:29Z","modified":"2026-07-28T22:25:30Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-22","CWE-200"],"updated_at":"2026-11-02T14:40:53.707378Z"}],"nvd":[{"id":"CVE-2026-54659","description":"Pagy is agnostic pagination in plain Ruby. From 43.0.0 until 43.5.6, Pagy::I18n.locale= in gem/lib/pagy/modules/i18n/i18n.rb stored locale values verbatim and later used them as \u003clocale\u003e.yml path components, allowing untrusted params[:locale] values with absolute paths or ../ sequences to create a file existence and readability oracle for YAML files. This issue is fixed in version 43.5.6.","status":"published","published":"2026-07-28T23:17:09.067Z","modified":"2026-10-23T23:10:00.157Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"}],"cwes":["CWE-22","CWE-200"],"updated_at":"2026-11-02T14:12:33.629616Z"}],"osv":[{"id":"CVE-2026-54659","title":"Pagy I18n locale option is not validated before being used in a file path","description":"Pagy is agnostic pagination in plain Ruby. From 43.0.0 until 43.5.6, Pagy::I18n.locale= in gem/lib/pagy/modules/i18n/i18n.rb stored locale values verbatim and later used them as \u003clocale\u003e.yml path components, allowing untrusted params[:locale] values with absolute paths or ../ sequences to create a file existence and readability oracle for YAML files. This issue is fixed in version 43.5.6.","status":"published","published":"2026-07-28T22:25:35.231Z","modified":"2026-10-28T02:31:12.441172985Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-200","CWE-22"],"updated_at":"2026-11-02T15:45:10.818486Z"},{"id":"GHSA-2xmw-f8j8-wfxc","title":"Pagy I18n locale option is not validated before being used in a file path","description":"### Summary\n\n`Pagy::I18n.locale=` did not validate its argument before using it as a\npath component to load the matching dictionary file (`\u003clocale\u003e.yml`). An\napplication that assigns untrusted input to the locale — e.g. the common\npattern `Pagy::I18n.locale = params[:locale]` — let that input influence\nwhich file Pagy attempted to load.\n\n### Details\n\nThe setter stored the value as-is, and the loader joined it into a path\nand read it:\n\n```ruby\n# gem/lib/pagy/modules/i18n/i18n.rb\ndef locale=(value)\n  Thread.current[:pagy_locale] = value.to_s\nend\n\n# ...later, when translating:\npath = pathnames.reverse.map { |p| p.join(\"#{locale}.yml\") }.find(\u0026:exist?)\ndictionary = YAML.load_file(path)[locale]\n```\n\nBecause the locale was used verbatim, a value such as an absolute path or\na `../`-style string redirected the lookup outside the locales directory.\nPagy's subsequent structural check (`dictionary['pagy']['p11n']`)\nprevents the file's contents from being returned, so this is **not** a\ndirect file read.\n\nFixed in 43.5.6 by constraining the locale to a BCP 47 shape before use:\n\n```ruby\nLOCALE_PATTERN = /\\A[a-zA-Z]{2,8}(-[a-zA-Z0-9]{1,8})*\\z/\n\ndef locale=(value)\n  Thread.current[:pagy_locale] = value.to_s[LOCALE_PATTERN]\nend\n```\n\nAny non-matching value (including `nil`) resolves to the default locale\nand never reaches the file lookup.\n\n### PoC\n\nIn an application that sets `Pagy::I18n.locale = params[:locale]`, the\nloader appends `.yml` and reads `\u003clocale\u003e.yml`, so the request param\ncontrols the target path. For example, pointing it at the app's\n`config/database.yml`:\n\n1. Send a request with `?locale=../../../config/database` (adjust the\n   number of `../` to reach the app root from the gem's `locales/`\n   directory).\n2. Pagy calls `YAML.load_file` on the resulting `…/config/database.yml`.\n3. The outcome differs by whether that `.yml` exists, is readable, parses\n   as YAML, and has Pagy's expected structure — an existing, readable\n   `config/database.yml` raises a different error than a non-existent\n   path (which silently falls back to the default locale). This yields a\n   file-existence / readability oracle for `.yml` paths, and the targeted\n   file is read into the process during the attempt.\n\n### Impact\n\nInformation disclosure (CWE-22 / CWE-200): a file-existence / readability\noracle for `.yml` paths on the host, plus a server-side read of\nattacker-chosen files into the process. The file contents are not\nreturned in the response.\n\nOnly applications that pass **unsanitized end-user input** into\n`Pagy::I18n.locale=` are affected. Applications that set the locale from\ntrusted values are not affected.\n\n**Patched:** pagy 43.5.6.\n**Workaround (if you cannot upgrade):** validate the locale before\nassigning it, e.g.\n`Pagy::I18n.locale = params[:locale].to_s[/\\A[a-zA-Z]{2,8}(-[a-zA-Z0-9]{1,8})*\\z/]`,\nor restrict it to your known set of locales.","status":"published","published":"2026-07-28T22:25:29Z","modified":"2026-07-28T22:41:45.721426Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-200","CWE-22"],"updated_at":"2026-11-02T15:46:35.050232Z"},{"id":"UBUNTU-CVE-2026-54659","description":"Pagy is agnostic pagination in plain Ruby. From 43.0.0 until 43.5.6, Pagy::I18n.locale= in gem/lib/pagy/modules/i18n/i18n.rb stored locale values verbatim and later used them as \u003clocale\u003e.yml path components, allowing untrusted params[:locale] values with absolute paths or ../ sequences to create a file existence and readability oracle for YAML files. This issue is fixed in version 43.5.6.","status":"published","published":"2026-07-28T23:17:00Z","modified":"2026-10-17T13:00:25.904050181Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T16:56:41.382716Z"}]}}