CVE-2021-35955
unknown
CVSS v3
—
CVSS v4 NEW
—
VIR risk
—
Description
Cross site scripting via HTML attributes in the back end
Predictions
Exploit likelihood
30%
Patch ETA
—
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| Packagist | contao/core-bundle | >=4.0.0,<4.4.56 | 4.4.56 |
| Packagist | contao/contao | >=4.0.0,<4.4.56 | 4.4.56 |
| Packagist | contao/contao | >=4.5.0,<4.9.18 | 4.9.18 |
| Packagist | contao/contao | >=4.10.0,<4.11.7 | 4.11.7 |
| Packagist | contao/core-bundle | >=4.5.0,<4.9.18 | 4.9.18 |
| Packagist | contao/core-bundle | >=4.10.0,<4.11.7 | 4.11.7 |
References
- https://github.com/contao/contao/security/advisories/GHSA-hr3h-x6gq-rqcp
- https://nvd.nist.gov/vuln/detail/CVE-2021-35955
- https://contao.org/en/news/contao-4-9-16-and-4-11-5-are-available.html
- https://contao.org/en/security-advisories/cross-site-scripting-via-html-attributes-in-the-back-end.html
- https://github.com/FriendsOfPHP/security-advisories/blob/master/contao/contao/CVE-2021-35955.yaml
- https://github.com/FriendsOfPHP/security-advisories/blob/master/contao/core-bundle/CVE-2021-35955.yaml
- https://github.com/contao/contao
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.