CVE-2025-61780
Rack has Possible Information Disclosure Vulnerability
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium5.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N |
| NVDNVD · Analyzed | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.55% · top 54% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.8.
Weakness
- CWE-200: Exposure of Sensitive Information to an Unauthorized Actor (opens in a new tab)All about CWE-200 and its CVEs
- CWE-441: Unintended Proxy or Intermediary ('Confused Deputy') (opens in a new tab)All about CWE-441 and its CVEs
- CWE-913: Improper Control of Dynamically-Managed Code Resources (opens in a new tab)All about CWE-913 and its CVEs
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- RubyGemsrackGHSA-r657-rxjc-j557 (opens in a new tab)
References (4)
- https://github.com/rack/rack/security/advisories/GHSA-r657-rxjc-j557 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/rack/rack/commit/57277b7741581fa827472c5c666f6e6a33abd784 (opens in a new tab)x_refsource_MISC
- https://github.com/rack/rack/commit/7e69f65eefe9cd2868df9f9f3b0977b86f93523a (opens in a new tab)x_refsource_MISC
- https://github.com/rack/rack/commit/fba2c8bc63eb787ff4b19bc612d315fda6126d85 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-r657-rxjc-j557 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2025-61780)Record last updated .