# CVE-2025-61780: ruby-rack: Rack is a modular Ruby web server interface CVE-2025-61780 is fixed in 3 products on 1 platform, first by ruby-rack 1.6.4-4ubuntu0.2+esm9, released October 10, 2025. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2025-61780 - Priority: Routine - CVSS: 5.3 (medium) - EPSS: 0.0055 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Oct 10, 2025 ## Description Rack is a modular Ruby web server interface. Prior to versions 2.2.20, 3.1.18, and 3.2.3, a possible information disclosure vulnerability existed in `Rack::Sendfile` when running behind a proxy that supports `x-sendfile` headers (such as Nginx). Specially crafted headers could cause `Rack::Sendfile` to miscommunicate with the proxy and trigger unintended internal requests, potentially bypassing proxy-level access restrictions. When `Rack::Sendfile` received untrusted `x-sendfile-type` or `x-accel-mapping` headers from a client, it would interpret them as proxy configuration directives. This could cause the middleware to send a "redirect" response to the proxy, prompting it to reissue a new internal request that was not subject to the proxy's access controls. An attacker could exploit this by setting a crafted `x-sendfile-type: x-accel-redirect` header, setting a crafted `x-accel-mapping` header, and requesting a path that qualifies for proxy-based acceleration. Attackers could bypass proxy-enforced restrictions and access internal endpoints intended to be protected (such as administrative pages). The vulnerability did not allow arbitrary file reads but could expose sensitive application routes. This issue only affected systems meeting all of the following conditions: The application used `Rack::Sendfile` with a proxy that supports `x-accel-redirect` (e.g., Nginx); the proxy did **not** always set or remove the `x-sendfile-type` and `x-accel-mapping` headers; and the application exposed an endpoint that returned a body responding to `.to_path`. Users should upgrade to Rack versions 2.2.20, 3.1.18, or 3.2.3, which require explicit configuration to enable `x-accel-redirect`. Alternatively, configure the proxy to always set or strip the header, or in Rails applications, disable sendfile completely. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | ruby-rack Debian 12.15 (bookworm) | 2.2.20-0+deb12u1 | [DEBIAN-CVE-2025-61780](https://patchblox.com/security/data/fix/linux/debian-cve-2025-61780.md) | Oct 10, 2025 | | Linux | ruby-rack Debian 13.5 (trixie) | 3.1.18-1~deb13u1 | [DEBIAN-CVE-2025-61780](https://patchblox.com/security/data/fix/linux/debian-cve-2025-61780.md) | Oct 10, 2025 | | Linux | ruby-rack Debian 14 | 3.1.18-1 | [DEBIAN-CVE-2025-61780](https://patchblox.com/security/data/fix/linux/debian-cve-2025-61780.md) | Oct 10, 2025 | | Linux | ruby-rack Ubuntu 18.04.6 LTS (bionic) | 1.6.4-4ubuntu0.2+esm9 | [ruby-rack 1.6.4-4ubuntu0.2+esm9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-ruby-rack-1.6.4-4ubuntu0.2-esm9.md) | Oct 10, 2025 | | Linux | ruby-rack Ubuntu 20.04 LTS (focal) | 2.0.7-2ubuntu0.1+esm8 | [ruby-rack 2.0.7-2ubuntu0.1+esm8](https://patchblox.com/security/data/fix/linux/ubuntu-focal-ruby-rack-2.0.7-2ubuntu0.1-esm8.md) | Oct 10, 2025 | | Linux | ruby-rack Ubuntu 22.04.1 LTS (jammy) | 2.1.4-5ubuntu1.2 | [ruby-rack 2.1.4-5ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-ruby-rack-2.1.4-5ubuntu1.2.md) | Oct 10, 2025 | | Linux | ruby-rack Ubuntu 24.04.5 LTS (noble) | 2.2.7-1ubuntu0.5 | [ruby-rack 2.2.7-1ubuntu0.5](https://patchblox.com/security/data/fix/linux/ubuntu-noble-ruby-rack-2.2.7-1ubuntu0.5.md) | Oct 10, 2025 | | Linux | ruby-rack Ubuntu 25.10 (questing) | 3.1.16-0.1ubuntu0.1 | [ruby-rack 3.1.16-0.1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-questing-ruby-rack-3.1.16-0.1ubuntu0.1.md) | Oct 10, 2025 | | Linux | rubygem-rack Fedora 43 | 1:3.1.19-1.fc43 | [FEDORA-2025-B6E0F437B6](https://patchblox.com/security/data/fix/linux/fedora-2025-b6e0f437b6.md) | Nov 4, 2025 | | Linux | rubygem-rack opensuse-leap 15.6 | 2.2.20-150000.3.34.1 | [SUSE-SU-2025:4273-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4273-1.md) | Nov 27, 2025 | | Linux | rubygem-rack sles 15.6 | 2.2.20-150000.3.34.1 | [SUSE-SU-2025:4273-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4273-1.md) | Nov 27, 2025 | | Linux | rubygem-rack sles 15.7 | 2.2.20-150000.3.34.1 | [SUSE-SU-2025:4273-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4273-1.md) | Nov 27, 2025 | | Linux | rubygem-rack-doc Fedora 43 | 1:3.1.19-1.fc43 | [FEDORA-2025-B6E0F437B6](https://patchblox.com/security/data/fix/linux/fedora-2025-b6e0f437b6.md) | Nov 4, 2025 | --- Data as of 2026-11-08T13:06:02Z UTC. 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