CVE-2021-21340
Cross-Site Scripting in Content Preview
TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 10.4.14, 11.1.1 it has been discovered that database fields used as descriptionColumn are vulnerable to cross-site scripting when their content gets previewed. A valid backend user account is needed to exploit this vulnerability. This is fixed in versions 10.4.14, 11.1.1 .
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
5.4
Cross-Site Scripting in Content Preview
TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 10.4.14, 11.1.1 it has been discovered that database fields used as descriptionColumn are vulnerable to cross-site scripting when their content gets previewed. A valid backend user account is needed to exploit this vulnerability. This is fixed in versions 10.4.14, 11.1.1 .
- Record
CVE-2021-21340- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2021-0653
5.4
TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 10.4.14, 11.1.1 it has been discovered that database fields used as descriptionColumn are vulnerable to cross-site scripting when their content gets previewed. A valid backend user account is needed to exploit this vulnerability. This is fixed in versions 10.4.14, 11.1.1 .
- Record
EUVD-2021-0653- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-fjh3-g8gq-9q92
5.4
Cross-Site Scripting in Content Preview
Problem
It has been discovered that database fields used as descriptionColumn are vulnerable to cross-site scripting when their content gets previewed in the page module. A valid backend user account is needed to exploit this vulnerability.
Solution
Update to TYPO3 versions 10.4.14, 11.1.1 that fix the problem described.
Credits
Thanks to Richie Lee who reported this issue and to TYPO3 framework merger Andreas Fernandez who fixed the issue.
References
- Record
GHSA-fjh3-g8gq-9q92- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
5.4
TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 10.4.14, 11.1.1 it has been discovered that database fields used as descriptionColumn are vulnerable to cross-site scripting when their content gets previewed. A valid backend user account is needed to exploit this vulnerability. This is fixed in versions 10.4.14, 11.1.1 .
- Record
CVE-2021-21340- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 3.5 Low
AV:N/AC:M/Au:S/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
5.4
TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 10.4.14, 11.1.1 it has been discovered that database fields used as descriptionColumn are vulnerable to cross-site scripting when their content gets previewed. A valid backend user account is needed to exploit this vulnerability. This is fixed in versions 10.4.14, 11.1.1 .
- Record
CVE-2021-21340- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-fjh3-g8gq-9q92
5.4
Cross-Site Scripting in Content Preview
Problem
It has been discovered that database fields used as descriptionColumn are vulnerable to cross-site scripting when their content gets previewed in the page module. A valid backend user account is needed to exploit this vulnerability.
Solution
Update to TYPO3 versions 10.4.14, 11.1.1 that fix the problem described.
Credits
Thanks to Richie Lee who reported this issue and to TYPO3 framework merger Andreas Fernandez who fixed the issue.
References
- Record
GHSA-fjh3-g8gq-9q92- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSVBIT-typo3-2021-21340 No score
TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 10.4.14, 11.1.1 it has been discovered that database fields used as descriptionColumn are vulnerable to cross-site scripting when their content gets previewed. A valid backend user account is needed to exploit this vulnerability. This is fixed in versions 10.4.14, 11.1.1 .
- Record
BIT-typo3-2021-21340- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
typo3/cms-backendPackagist |
10.0.0 to 10.4.13 | 10.4.14 |
typo3/cms-backendPackagist |
11.0.0 to 11.1.0 | 11.1.1 |
typo3/cms-corePackagist |
10.0.0 up to 10.4.14 | 10.4.14 |
typo3/cms-corePackagist |
11.0.0 up to 11.1.1 | 11.1.1 |
typo3/cmsPackagist |
10.0.0 up to 10.4.14 | 10.4.14 |
typo3/cmsPackagist |
11.0.0 up to 11.1.1 | 11.1.1 |
typo3Bitnami |
10.0.0 up to 10.4.14, 11.0.0 up to 11.1.1 | 10.4.1411.1.1 |
typo3/cms-backendPackagist |
10.0.0 up to 10.4.14, plus listed versions v10.0.0v10.1.0v10.2.0v10.2.1v10.2.2 Show 15 moreShow lessv10.3.0v10.4.0v10.4.1v10.4.10v10.4.11v10.4.12v10.4.13v10.4.2v10.4.3v10.4.4v10.4.5v10.4.6v10.4.7v10.4.8v10.4.9 |
10.4.14 |
typo3/cms-backendPackagist |
11.0.0 up to 11.1.1, plus listed versions v11.0.0v11.1.0 |
11.1.1 |
typo3/cms-corePackagist |
10.0.0 up to 10.4.14, plus listed versions v10.0.0v10.1.0v10.2.0v10.2.1v10.2.2 Show 15 moreShow lessv10.3.0v10.4.0v10.4.1v10.4.10v10.4.11v10.4.12v10.4.13v10.4.2v10.4.3v10.4.4v10.4.5v10.4.6v10.4.7v10.4.8v10.4.9 |
10.4.14 |
typo3/cms-corePackagist |
11.0.0 up to 11.1.1, plus listed versions v11.0.0v11.1.0 |
11.1.1 |
typo3/cmsPackagist |
10.0.0 up to 10.4.14, plus listed versions v10.0.0v10.1.0v10.2.0v10.2.1v10.2.2 Show 15 moreShow lessv10.3.0v10.4.0v10.4.1v10.4.10v10.4.11v10.4.12v10.4.13v10.4.2v10.4.3v10.4.4v10.4.5v10.4.6v10.4.7v10.4.8v10.4.9 |
10.4.14 |
typo3/cmsPackagist |
11.0.0 up to 11.1.1, plus listed versions v11.0.0v11.1.0 |
11.1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-21340 is a medium vulnerability (CVSS 5.4) in Typo3, published March 23, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.87%, the 59th percentile. Fixed in typo3/cms-backend 10.4.14.
References
github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-fjh3-g8gq-9q92
packagist.org/packages/typo3/cms-backend
typo3.org/security/advisory/typo3-core-sa-2021-007
nvd.nist.gov/vuln/detail/CVE-2021-21340
github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2021-21340.yaml
github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2021-21340.yaml
github.com/advisories/GHSA-fjh3-g8gq-9q92