CVE-2020-6817

bleach.clean behavior parsing style attributes could result in a regular expression denial of service (ReDoS). Calls to bleach.clean with an allowed tag with an allowed style attribute are vulnerable to ReDoS. For example, bleach.clean(..., attributes={'a': ['style']}).

Score

CVSS 3.1 7.5 High

Status

Modified - security@mozilla.org

Published

2023-02-16

Last modified

2025-03-19

Weaknesses

CWE-1333

Affected products

• Bleach (Mozilla)
• Mozilla Bleach (Mozilla)

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1623633
• https://github.com/mozilla/bleach/security/advisories/GHSA-vqhp-cxgc-6wmm