CVE-2026-57566: Readest: Unauthenticated SSRF / open request proxy in /api/opds/proxy

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 10 Nov 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.6%

EPSS score, percentile 48.3 of all scored records. A probability estimated by FIRST, not a report of exploitation.

CISA's SSVC assessment in the CVE record lists exploitation as poc.

How severe?

9.3 Critical

CVSS v3.1 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

No patch or vendor advisory is listed in the CVE record. Check readest's advisories.

Which versions are affected?

Affected

• < 0.11.10

Versions by product

Source: CISA KEV 2026.11.10, as of 10 Nov 2026; FIRST EPSS, as of 12 Nov 2026; CVE List, as of 12 Nov 2026. About the data.

Description

Readest: Unauthenticated SSRF / open request proxy in /api/opds/proxy

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.

Source: CVE List, as of 12 Nov 2026. About the data.

What to do

Advisories and patches

No patch, vendor advisory or mitigation is listed in the CVE record. Check readest's own security advisories for a fix, and compare your version with the affected versions below.

This summary is based on the CVE record as of 12 Nov 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

Source: CVE List, as of 12 Nov 2026. About the data.

Timeline