CVE-2026-42883: Auth Bypass (CVSS 6.5)

Description

Audiobookshelf is a self-hosted audiobook and podcast server. Prior to 2.32.2, the GET /api/libraries/:id/download endpoint validates that the requesting user has access to the library specified in the URL path, but fetches downloadable items solely by attacker-provided IDs without constraining them to that library. An authenticated user with download permission and access to any one library can exfiltrate the full file contents of items belonging to any other library, including libraries they are explicitly denied access to. This vulnerability is fixed in 2.32.2.

Is your site exposed to CVE-2026-42883?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS — Exploit Prediction

0.0003

Probability of exploitation

0.10%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-863 Incorrect Authorization

References

Other References

https://github.com/advplyr/audiobookshelf/security/advisories/GHSA-6rvg-w3f5-9gq5 https://github.com/advplyr/audiobookshelf/security/advisories/GHSA-6rvg-w3f5-9gq5

Frequently Asked Questions

What is CVE-2026-42883? +

Audiobookshelf is a self-hosted audiobook and podcast server. Prior to 2.32.2, the GET /api/libraries/:id/download endpoint validates that the requesting user has access to the library specified in the URL path, but fetches downloadable items solely by attacker-provided IDs without constraining them to that library. An authenticated user with download permission and access to any one library can exfiltrate the full file contents of items belonging to any other library, including libraries they are explicitly denied access to. This vulnerability is fixed in 2.32.2. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-42883? +

CVE-2026-42883 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0003, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-42883? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-50008

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. From version …

CVE-2026-42571

Pelican is a platform for creating data federations. From versions 7.21.0 to before 7.21.5, 7.22.0 to before 7.22.3, 7.23.0 to …

CVE-2026-42137

Kirby is an open-source content management system. Prior to versions 4.9.0 and 5.4.0, `pages.access/list` and `files.access/list` permissions are not consistently …

CVE-2026-54358

An incorrect authorization vulnerability in MISP allows an organization administrator to target site administrator accounts belonging to the same organization …

CVE-2026-42160

Data Space Portal is an open-source Software as a Service (SaaS) solution designed to streamline Dataspace management. From version 2.1.1 …

CVE-2026-42604

Actual is a local-first personal finance tool. The `POST /openid/config` endpoint in Actual Budget's sync-server versions <= 26.4.0 exposes the …

CVE-2026-42883