CVE-2025-68142

PyMdown Extensions has ReDOS bug in Figure Capture extension

Published Dec 16, 2025 CVSS 4.0 · 2.7 Low EPSS < 1% KEV · Not listed
Description
PyMdown Extensions is a set of extensions for the `Python-Markdown` markdown project. Versions prior to 10.16.1 have a ReDOS bug found within the figure caption extension (`pymdownx.blocks.caption`). In systems that take unchecked user content, this could cause long hanges when processing the data if a malicious payload was crafted. This issue is patched in Release 10.16.1. As a workaround, those who process unknown user content without timeouts or other safeguards in place to prevent really large, malicious content being aimed at systems may avoid the use of `pymdownx.blocks.caption` until they're able to upgrade.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-r6h4-mm7h-8pmq PyMdown Extensions has a ReDOS bug in its Figure Capture extension
History
Type Values Removed Values Added
First Time appeared Facelessuser
Facelessuser pymdown Extensions
CPEs cpe:2.3:a:facelessuser:pymdown_extensions:*:*:*:*:*:*:*:*
Vendors & Products Facelessuser
Facelessuser pymdown Extensions
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

threat_severity

Low

Type Values Removed Values Added
Description PyMdown Extensions is a set of extensions for the `Python-Markdown` markdown project. Versions prior to 10.16.1 have a ReDOS bug found within the figure caption extension (`pymdownx.blocks.caption`). In systems that take unchecked user content, this could cause long hanges when processing the data if a malicious payload was crafted. This issue is patched in Release 10.16.1. As a workaround, those who process unknown user content without timeouts or other safeguards in place to prevent really large, malicious content being aimed at systems may avoid the use of `pymdownx.blocks.caption` until they're able to upgrade.
Title PyMdown Extensions has ReDOS bug in Figure Capture extension
Weaknesses CWE-1333
References
Metrics cvssV4_0

{'score': 2.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Dec 17, 2025, 6:51 PM
Reserved
Dec 15, 2025, 6:15 PM
Status
Analyzed
Published
Dec 16, 2025, 6:16 PM
Modified
Jun 17, 2026, 9:58 AM
Severity
Low
Public date
Dec 16, 2025, 6:06 PM