CVE-2026-42887 Audiobookshelf: Stored Cross-Site Scripting in Login Page Custom Message
Administrators can inject malicious scripts into the login page, potentially compromising user sessions and data.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-42887?
CVE-2026-42887 is a medium-severity cross-site scripting vulnerability in advplyr audiobookshelf, published on 11 May 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
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.
Weakness: CWE-79
Which versions are affected by CVE-2026-42887?
How do I fix CVE-2026-42887?
No fix has been published for CVE-2026-42887 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-42887 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42887 exists.
Sources
Also known as GHSA-cx29-ghq2-9cm4.