GHSA-r657-rxjc-j557 · Severity: medium · Ecosystem: rubygems — Rack has a Possible Information Disclosure Vulnerability
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.
Conclusion & alert: CVE-2025-61780 is rated Low Risk (25.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.03%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-03-08 | 0.05% | 0.03% | -0.03% |
| 2 | 2026-02-09 | 0.03% | 0.05% | +0.02% |
| 3 | 2025-10-11 | — | 0.03% | — |
Full EPSS history (3 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.8 | 3.1 | MEDIUM |
|
3.9 | 1.4 | [email protected] |
| 5.3 | 3.1 | MEDIUM |
|
3.9 | 1.4 | [email protected] |
GHSA-r657-rxjc-j557 · Severity: medium · Ecosystem: rubygems — Rack has a Possible Information Disclosure Vulnerability
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2025-61780 not yet assigned priority: Debian including 1 source packages (ruby-rack), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2025-61780 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2025-61780 |
suse
|
medium | — | https://www.suse.com/security/cve/CVE-2025-61780/ |
ubuntu
|
medium | CVE-2025-61780 medium priority: Ubuntu including 1 source packages (ruby-rack), 9 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): released 6, ignored 2, needs-triage 1. | https://ubuntu.com/security/CVE-2025-61780 |