Description
An XSS vulnerability was discovered in python-lxml's clean module versions before 4.6.3. When disabling the safe_attrs_only and forms arguments, the Cleaner class does not remove the formaction attribute allowing for JS to bypass the sanitizer. A remote attacker could exploit this flaw to run arbitrary JS code on users who interact with incorrectly sanitized HTML. This issue is patched in lxml 4.6.3.
No analysis available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-2606-1 | lxml security update |
Debian DSA |
DSA-4880-1 | lxml security update |
EUVD |
EUVD-2021-0116 | An XSS vulnerability was discovered in python-lxml's clean module versions before 4.6.3. When disabling the safe_attrs_only and forms arguments, the Cleaner class does not remove the formaction attribute allowing for JS to bypass the sanitizer. A remote attacker could exploit this flaw to run arbitrary JS code on users who interact with incorrectly sanitized HTML. This issue is patched in lxml 4.6.3. |
Github GHSA |
GHSA-jq4v-f5q6-mjqq | lxml vulnerable to Cross-Site Scripting |
Ubuntu USN |
USN-4896-1 | lxml vulnerability |
Ubuntu USN |
USN-4896-2 | lxml vulnerability |
References
History
Wed, 17 Dec 2025 22:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Status: PUBLISHED
Assigner: mitre
Published:
Updated: 2025-12-17T21:31:43.446Z
Reserved: 2021-03-21T00:00:00.000Z
Link: CVE-2021-28957
Updated: 2024-08-03T21:55:12.376Z
Status : Modified
Published: 2021-03-21T05:15:13.367
Modified: 2025-12-17T22:15:56.740
Link: CVE-2021-28957
OpenCVE Enrichment
No data.
Weaknesses
Debian DLA
Debian DSA
EUVD
Github GHSA
Ubuntu USN