CVE-2021-21340 json
Cross-Site Scripting in Content Preview
published 2021-03-23 5 y ago modified 2026-07-08 4 mo ago also BIT-typo3-2021-21340 , EUVD-2021-0653 , GHSA-fjh3-g8gq-9q92
- cvss
- 5.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.9%
- EPSS 0.9% chance of exploitation in 30 days, percentile 59%
- public exploits
- 0
- none known
Summary
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 .
Patch / fix
- packagist typo3/cms-backend 10.4.14, 11.1.1
- packagist typo3/cms-core 10.4.14, 11.1.1
- packagist typo3/cms 10.4.14, 11.1.1
- bitnami typo3 10.4.14, 11.1.1
- typo3 typo3 10.4.14, 11.1.1
Exploit prediction
0.87% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
| GitHub | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
| NVD | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 3.5 | AV:N/AC:M/Au:S/C:N/I:P/A:N |
| OSV | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| packagist | typo3/cms-backend | >=10.0.0, <10.4.14 >=11.0.0, <11.1.1 |
10.4.14 11.1.1 |
| packagist | typo3/cms-core | >=10.0.0, <10.4.14 >=11.0.0, <11.1.1 |
10.4.14 11.1.1 |
| packagist | typo3/cms | >=10.0.0, <10.4.14 >=11.0.0, <11.1.1 |
10.4.14 11.1.1 |
| bitnami | typo3 | >=10.0.0, <10.4.14 >=11.0.0, <11.1.1 |
10.4.14 11.1.1 |
Affected products
- TYPO3 TYPO3.CMS
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
typo3.org
/security/advisory/typo3-core-sa-2021-007
web, vendor-advisory
-
github.com
/TYPO3/TYPO3.CMS/security/advisories/GHSA-fjh3-g8gq-9q92
web, third-party-advisory
-
packagist.org
/packages/typo3/cms-backend
web, release-notes, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-21340
advisory
-
github.com
/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2021-21340.yaml
web
-
github.com
/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2021-21340.yaml
web
Sources
- CVE List CVE-2021-21340
- GitHub Advisory GHSA-fjh3-g8gq-9q92
- NVD CVE-2021-21340
- OSV BIT-typo3-2021-21340
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