Cross-Site-Request-Forgery in Backend

Exploitation

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

CVSS

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

EPSS

• CVE-2021-41113: 0.64% estimated exploitation activity in the next 30 days; percentile 50.71 (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.

Meta CVSS: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C (8.2) Problem It has been discovered that the new TYPO3 v11 feature that allows users to create and share deep links in the backend user interface is vulnerable to cross-site-request-forgery. The impact is the same as described in TYPO3-CORE-SA-2020-006 (CVE-2020-11069). However, it is not limited to the same site context and does not require the attacker to be authenticated. In a worst case scenario, the attacker could create a new admin user account to compromise the system. To successfully carry out an attack, an attacker must trick his victim to access a compromised system. The victim must have an active session in the TYPO3 backend at that time. The following Same-Site cookie settings in $GLOBALS[TYPO3CONFVARS][BE][cookieSameSite] are required for an attack to be successful: SameSite=strict: malicious evil.example.org invoking TYPO3 application at good.example.org SameSite=lax or none: malicious evil.com…

Published by the source

5 Oct 2021, 20:23 UTC

Last modified by the source

5 Feb 2024, 11:18 UTC

Source last checked

26 Oct 2026, 14:15 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-657m-v5vm-f6rw

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# Patch Next advisory brief: CVE-2021-41113

Advisory: Cross-Site-Request-Forgery in Backend
IDs: CVE-2021-41113, GHSA-657m-v5vm-f6rw
Record: https://patchnext.com/advisories/cve-2021-41113 (revision 1, source checked 26 Oct 2026, 14:15 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: typo3/cms-core 11.5.0; typo3/cms 11.5.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist typo3/cms-core: affected >= 11.2.0, < 11.5.0; fixed in 11.5.0
- Packagist typo3/cms: affected >= 11.2.0, < 11.5.0; fixed in 11.5.0

## Suggested inspection (read-only)
- Packagist typo3/cms-core: check the installed version with your package manager.
- Packagist typo3/cms: 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 typo3/cms-core, typo3/cms.
- 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-657m-v5vm-f6rw (GitHub-reviewed advisory GHSA-657m-v5vm-f6rw lists affected ranges: Packagist typo3/cms-core >=11.2.0 =11.2.0 <11.5.0)

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