🛡️ CVE-2020-6817 on Debian — python-bleach

⚪ Unknown ✅ No Known Exploit OSV

N/A

CVSS Score

0 Low4 Medium7 High9 Critical10

Description

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']}).

Distribution advisory

This page covers CVE-2020-6817 as tracked by Debian, for the package python-bleach. The fix is available in version 3.1.4-1; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

Affected software

DEBIAN-CVE-2020-6817 is recorded against 1 package.

python-bleach (fixed in 3.1.4-1)

Timeline and source

Published on 16 February 2023 and last revised on 15 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

security-tracker.debian.org (Advisory)

CVE-2020-6817 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Ubuntu

Details

Severity Unknown

CVSS Score N/A

CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE N/A

Public Exploit ✅ No

Source OSV

Published 2023-02-16

Updated 2026-08-20

Modified 2026-08-15

Fix URL N/A

Affected Packages

Software	From version	Fixed in
python-bleach	—	3.1.4-1

References

ADVISORY https://security-tracker.debian.org/tracker/CVE-2020-6817

🔗 NVD 🔗 Mitre

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