Bug 2512227 (CVE-2026-61632)

Summary: CVE-2026-61632 pymdown-extensions: PyMdown Extensions: Information disclosure via path traversal in b64 extension
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: abarbaro, alizardo, dschmidt, jchui, jhe, jlanda, kshier, ktsao, nboldt, oaljalju, psrna, simaishi, stcannon, teagle, yguenane
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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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.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2512417, 2512418    
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Description OSIDB Bzimport 2026-08-06 22:23:26 UTC 
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.