Credential capture via unsanitized login message
Published May 11, 2026 · Updated May 11, 2026
Stored XSS in Audiobookshelf before 2.33.0 allows remote authenticated users to capture credentials from users who visit the login page. The login view inserts authLoginCustomMessage from /api/auth-settings into the page with v-html without escaping or sanitizing its HTML. Administrative privileges are required to save the payload, and execution occurs when a logged-out user loads the login form, exposing entered usernames and passwords.
Summary
What happened
Stored XSS in Audiobookshelf before 2.33.0 allows remote authenticated users to capture credentials from users who visit the login page. The login view inserts authLoginCustomMessage from /api/auth-settings into the page with v-html without escaping or sanitizing its HTML. Administrative privileges are required to save the payload, and execution occurs when a logged-out user loads the login form, exposing entered usernames and passwords.
The record
- CVE
- CVE-2026-42887
- Published
- May 11, 2026
- Updated
- May 11, 2026
- Vendor
- advplyr
- Product
- Audiobookshelf
- Classifications
- T1056.002
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- May 11, 2026CVE publishedPublication date reported by the CVE source.
- May 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.33.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Upstream authLoginCustomMessage stored-XSS proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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