CVE-2020-6817

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Published Feb 16, 2023 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed

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']}).

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Mozilla

Mozilla Bleach

affected

Version	Status	Constraints
`unspecified`	affected	< 3.1.4

Configuration 1 [-]

cpe:2.3:a:mozilla:bleach:*:*:*:*:*:*:*:*

No data.

No data available yet.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source	ID	Title
Debian DLA	DLA-2167-1	python-bleach security update
EUVD	EUVD-2020-0056	regular expression denial-of-service (ReDoS) in Bleach
Github GHSA	GHSA-vqhp-cxgc-6wmm	regular expression denial-of-service (ReDoS) in Bleach
Ubuntu USN	USN-8077-1	Bleach vulnerabilities

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.718% probability within 30 days)

Exploitation poc

Automatable yes

Technical Impact partial

References

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

History

Mar 19, 2025 4:15 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Subscriptions

Mozilla Bleach

Weaknesses

CWE-1333

Sources

CVE record Updated: Mar 19, 2025, 3:21 PM

Status: PUBLISHED
Assigner: mozilla
Published: Feb 16, 2023, 12:00 AM
Updated: Mar 19, 2025, 3:21 PM
Reserved: Jan 10, 2020, 12:00 AM

View source JSON

Vulnrichment Updated: Aug 4, 2024, 9:11 AM

Updated: Aug 4, 2024, 9:11 AM

NVD Updated: Jun 17, 2026, 3:23 AM

Status: Modified
Published: Feb 16, 2023, 10:15 PM
Modified: Jun 17, 2026, 3:23 AM

View source JSON

Red Hat No data

No data.

OpenCVE enrichment No data

No data.

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