Mautic vulnerable to stored cross-site scripting in description field

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.6 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2021-27915: 0.62% estimated exploitation activity in the next 30 days; percentile 49.78 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact Prior to the patched version, there is an XSS vulnerability in the description fields within the Mautic application which could be exploited by a logged in user of Mautic with the appropriate permissions. This could lead to the user having elevated access to the system. Patches Update to 4.4.12 Workarounds None References - https://owasp.org/www-project-top-ten/2017/A72017-Cross-SiteScripting(XSS) - https://owasp.org/www-project-web-security-testing-guide/latest/4-WebApplicationSecurityTesting/07-InputValidationTesting/02-TestingforStoredCrossSiteScripting If you have any questions or comments about this advisory: Email us at security@mautic.org

Published by the source

11 Apr 2024, 21:36 UTC

Last modified by the source

30 Sep 2024, 13:44 UTC

Source last checked

26 Oct 2026, 14:26 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-2rc5-2755-v422

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2021-27915

Advisory: Mautic vulnerable to stored cross-site scripting in description field
IDs: CVE-2021-27915, GHSA-2rc5-2755-v422
Record: https://patchnext.com/advisories/cve-2021-27915 (revision 1, source checked 26 Oct 2026, 14:26 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: mautic/core 4.4.12. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist mautic/core: affected >= 1.0.0-beta2, < 4.4.12; fixed in 4.4.12

## Suggested inspection (read-only)
- Packagist mautic/core: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on mautic/core.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-2rc5-2755-v422 (GitHub-reviewed advisory GHSA-2rc5-2755-v422 lists affected ranges: Packagist mautic/core >=1.0.0-beta2 <4.4.12)

Commands are suggestions: review each one before running it.