Vulnerability in Mozilla Bleach
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']}).
Vulnerability class: ReDoS (Regular Expression Denial of Service)
EPSS: 0.007 (50.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Mozilla Bleach
- Mozilla Bleach — versions unspecified
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Exploit, Issue Tracking)
Frequently asked questions
- What is CVE-2020-6817?
- CVE-2020-6817 is a high-severity vulnerability in Mozilla Bleach, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2023-02-16.
- How severe is CVE-2020-6817?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2020-6817 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.