CVE-2026-57566

CRITICAL
INFO Priority: 0.05 BB Relevance: 79/100
Published: 2026-11-04 Modified: 2026-11-12 First seen: 2026-11-04 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction Conf. Impact Scope Change

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Changed
C: High
I: Low
A: None

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 Software (2)

VendorProductVersion
readest readest < 0.11.10
readest readest < 0.11.10

Bug Bounty Relevance

79 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

9.3 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N

EPSS — Exploitation Probability

0.58%
Raw Score 0.005810
Percentile 48.3%
Date 2026-11-13

EPSS Trend

2026-11-13
0.00581
2026-11-12
0.00581
2026-11-10
0.00581
2026-11-09
0.00581
2026-11-08
0.00581
2026-11-07
0.00581
2026-11-06
0.00581
2026-11-05
0.00581

Intelligence Sources

mitre ref →
nvd ref →