Neos CMS Cross Site Scripting vulnerability

Exploitation

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

CVSS

5.4 · CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

EPSS

• CVE-2023-37611: 0.71% estimated exploitation activity in the next 30 days; percentile 53.42 (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.

Cross Site Scripting (XSS) vulnerability in Neos CMS 8.3.3 allows a remote authenticated attacker to execute arbitrary code via a crafted SVG file uploaded to the neos/management/media component. To make use of this attack vector, the attacker must either be able to upload a maliciously crafted file or coerce someone with the needed access to upload said file to Neos. Even if such a file is uploaded and subsequently delivered, it is possible to use CSP to protect against attacks being executed from such a file.

Published by the source

19 Sep 2023, 00:30 UTC

Last modified by the source

16 Jan 2024, 17:08 UTC

Source last checked

26 Oct 2026, 14:14 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-6qjf-7g3j-qx25

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# Patch Next advisory brief: CVE-2023-37611

Advisory: Neos CMS Cross Site Scripting vulnerability
IDs: CVE-2023-37611, GHSA-6qjf-7g3j-qx25
Record: https://patchnext.com/advisories/cve-2023-37611 (revision 1, source checked 26 Oct 2026, 14:14 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: neos/media-browser 8.3.9, 8.2.11, 8.1.11, 8.0.16, 7.3.19. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist neos/media-browser: affected < 7.3.19; >= 8.0.0, < 8.0.16; >= 8.1.0, < 8.1.11; >= 8.2.0, < 8.2.11; >= 8.3.0, < 8.3.9; fixed in 8.0.16, 7.3.19, 8.1.11, 8.2.11, 8.3.9

## Suggested inspection (read-only)
- Packagist neos/media-browser: 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 neos/media-browser.
- 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-6qjf-7g3j-qx25 (GitHub-reviewed advisory GHSA-6qjf-7g3j-qx25 lists affected ranges: Packagist neos/media-browser >=0 =8.0.0 =8.1.0 =8.2.0 =8.3.0 <8.3.9)

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