Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-08-06T20:59:20 pymdown-extensions: PyMdown Extensions: Information disclosure via path traversal in b64 extension 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N CWE-22

PyMdown Extensions is a set of extensions for the Python-Markdown markdown project. In versions up to and including 10.21.3, the b64 extension is vulnerable to a path traversal that discloses arbitrary files: it inlines images referenced by <img src="..."> by joining the src onto the configured base_path with os.path.normpath and opening the result directly, without verifying that the resolved path stays inside base_path. As a result, an src containing ../ sequences or an absolute path reads a file outside base_path as long as it has an allowed image extension (.png, .jpg, .jpeg, .gif, .svg), and the file's contents are then base64-encoded into the rendered output, disclosing them. An application that renders untrusted Markdown with pymdownx.b64 enabled can therefore leak the contents of image-extension files readable by the process to whoever controls the Markdown or views the output, a targeted file-read bounded by the extension check. This issue has been fixed in version 11.0.

A flaw was found in PyMdown Extensions. The `b64` extension, used for inlining images in Markdown, is vulnerable to a path traversal issue. An attacker can craft untrusted Markdown with specially formed image source (`<img src="...">`) containing directory traversal sequences (e.g., `../`) or absolute paths. This allows the attacker to read and disclose the contents of arbitrary files on the system, provided they have an allowed image extension, leading to information disclosure.

Moderate: This flaw in PyMdown Extensions allows information disclosure via path traversal when the `b64` extension is enabled in applications processing untrusted Markdown. An attacker can craft malicious image references to read arbitrary files with specific extensions from the system. The impact is limited to files readable by the process and requires the `b64` extension to be active. Red Hat Developer Hub Fix deferred rhdh/rhdh-hub-rhel9 Red Hat Hardened Images Not affected grafana12.4 Red Hat Hardened Images Not affected grafana13.1 Red Hat Hardened Images Not affected trivy Red Hat OpenShift Container Platform 4 Fix deferred openshift4/ose-olm-catalogd-rhel9 Self-service automation portal 2 Fix deferred ansible-automation-platform/bootc-automation-portal-rhel9 https://www.cve.org/CVERecord?id=CVE-2026-61632 https://nvd.nist.gov/vuln/detail/CVE-2026-61632 https://github.com/facelessuser/pymdown-extensions/releases/tag/11.0 https://github.com/facelessuser/pymdown-extensions/security/advisories/GHSA-9xwg-3r6f-jcx2