Vulnerability · Published Jun 1, 2026 · Assigned by VulnCheck

CVE-2026-48559Lightweight Music Server 3.76.0 Stored XSS via Media File Metadata Tags

Medium 5.4

In plain English

A medium-severity cross-site scripting in lms from epoupon. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities).

Severity (CVSS 3.1)5.4Medium

Exploit odds (30 days)0.2%top 93.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Lightweight Music Server (LMS) though 3.76.0 contains a stored cross-site scripting vulnerability that allows attackers to execute arbitrary JavaScript by embedding malicious HTML in media file metadata tags such as GENRE, ARTIST, or ALBUM. Attackers can introduce a crafted media file into the victim's library, causing the payload to be saved during library scanning and executed automatically in the web interface due to tag content being rendered using Wt::TextFormat::UnsafeXHTML without sanitization in src/lms/ui/Utils.cpp.

Affected products (as reported)

Vendor	Product	Versions
epoupon	lms	0 – through 3.76.0

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

References

https://www.zeroscience.mk/#/advisories/ZSL-2026-5987 technical-description, exploit
https://github.com/epoupon/lms/issues/844 issue-tracking
https://github.com/epoupon/lms/milestone/94
https://www.vulncheck.com/advisories/lightweight-music-server-stored-xss-via-media-file-metadata-tags third-party-advisory