Vulnerability · Published Nov 4, 2026 · Assigned by GitHub_M
CVE-2026-57566Readest: Unauthenticated SSRF / open request proxy in /api/opds/proxy
Critical 9.3
In plain English
A critical-severity server-side request forgery in readest from readest. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities).
Official description
Readest is a modern, feature-rich ebook reader designed for seamless cross-platform access and an intuitive reading experience. Prior to 0.11.10, the unauthenticated /api/opds/proxy route in apps/readest-app/src/app/api/opds/proxy/route.ts accepted an attacker-controlled URL and fetched it server-side without restricting the scheme, blocking private, loopback, link-local, or metadata hosts, or revalidating destinations during automatic redirect following. The route also accepted caller-controlled outbound headers and Authorization values and reflected the upstream status and response body. A remote attacker could use the service as an open request proxy and, on Node, Docker, or other self-hosted deployments with internal-network access, retrieve cloud metadata or internal-service responses. Cloudflare Workers deployments restrict access to link-local and private destinations, which reduces the internal-network impact there, but the unauthenticated public fetch-and-reflect behavior remains. This issue is fixed in version 0.11.10.
Affected products (as reported)
Weakness: CWE-918 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
References
- https://github.com/readest/readest/security/advisories/GHSA-c7mm-g2j2-98cx x_refsource_CONFIRM
- https://github.com/readest/readest/pull/4638 x_refsource_MISC
- https://github.com/readest/readest/commit/495783d04516d05b2eb10f8f8bad297d436b36de x_refsource_MISC
- https://github.com/readest/readest/releases/tag/v0.11.10 x_refsource_MISC