Vulnerability · Published May 28, 2026 · Assigned by GitHub_M

CVE-2026-44657MantisBT: Stored XSS in File Download

High 7.5

In plain English

A high-severity cross-site scripting in mantisbt from mantisbt. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 29% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)7.5High

Exploit odds (30 days)0.3%top 71.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Mantis Bug Tracker (MantisBT) is an open source issue tracker. Prior to 2.28.2, using show_inline=1 parameter and a valid file_show_inline_token CSRF token on file_download.php, an attacker can execute code by uploading a crafted XHTML attachment referencing a JavaScript attachment. This vulnerability is fixed in 2.28.2.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	mantisbt/mantisbt	2.28.2	GHSA-p6fr-rxq7-xcg8

Affected products (as reported)

Vendor	Product	Versions
mantisbt	mantisbt	< 2.28.2

Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N

References

https://github.com/mantisbt/mantisbt/security/advisories/GHSA-p6fr-rxq7-xcg8 x_refsource_CONFIRM
https://github.com/mantisbt/mantisbt/security/advisories/GHSA-9c3j-xm6v-j7j3 x_refsource_MISC
https://github.com/mantisbt/mantisbt/commit/26647b2e68ba30b9d7987d4e03d7a16416684bc2 x_refsource_MISC
https://mantisbt.org/bugs/view.php?id=37020 x_refsource_MISC