CVE-2026-42887
CWE-79Published: May 11, 2026· Updated: May 12, 2026
Official Description
Audiobookshelf is a self-hosted audiobook and podcast server. Prior to 2.33.0, a stored cross-site scripting (XSS) vulnerability exists in the Login Page due to improper sanitization of the authLoginCustomMessage field of the /api/auth-settings endpoint. An attacker with administrative privileges can inject arbitrary HTML/JavaScript that will be rendered on the login page for all users. This vulnerability is fixed in 2.33.0.
Technical Analysis
CVE-2026-42887 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 4.5.
From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.
CVSS v3.1 Vector Breakdown
Exploit & PoC Resources
All References (2)
Quick Facts
Related CVEs (CWE-79)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-42887 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts