Medium [CVE-2026-59922] Denial of Service via crafted input
This medium-severity Red Hat Linux advisory covers CVE-2026-59922 affecting Migration Toolkit for Applications 8, Red Hat OpenShift AI (RHOAI), Red Hat OpenShift Container Platform 4.
Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.
VulniPulse record published Record updated
Summary
Mistune is a Python Markdown parser with renderers and plugins.
Prior to 3.3.0, a run of closed tilde, equals-sign, or caret marker pairs around a character causes quadratic work in src/mistune/plugins/formatting.py when the strikethrough, mark, or insert plugin scans for matching markers from each possible start position, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0.
A remote attacker could exploit this vulnerability by providing specially crafted input containing specific marker pairs (tilde, equals-sign, or caret). This crafted input causes the parser to perform quadratic work, leading to excessive CPU consumption.
This can result in a denial of service (DoS) for the affected system. This Moderate flaw in the Mistune Python Markdown parser can lead to a denial of service.
This vulnerability primarily affects Red Hat products where the strikethrough, mark, or insert plugins are explicitly enabled, as these are not part of Mistune's default configuration. Red Hat severity: Moderate — CVSS 6.5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).
Weakness: CWE-1333. Affected Red Hat products: Migration Toolkit for Applications 8; Red Hat OpenShift AI (RHOAI); Red Hat OpenShift Container Platform 4.
Red Hat does not currently list a fixing RHSA for this CVE.
Is CVE-2026-59922 exploited?
No exploitation is reported in the sources VulniPulse tracks: CVE-2026-59922 is not in the CISA KEV catalog (checked ) and this advisory does not report exploitation. That is not proof the vulnerability cannot be exploited.
How do I fix CVE-2026-59922?
Upgrade to a fixed release named by Red Hat:
- 3.3.0
Confirm against the vendor advisory before you patch.
- < 3.3.0
Official advisory · high-confidence parse· fetched 3 days ago·verify at source
Mitigation checklist
- To mitigate this vulnerability, disable the `strikethrough`, `mark`, and `insert` plugins if they are not essential for your application's functionality. These plugins are not enabled by default in Mistune. Consult your application's documentation for specific instructions on how to configure or disable Mistune plugins. If the application does not explicitly enable these plugins, no further action is required.
Official advisory · high-confidence parse· fetched 3 days ago·verify at source
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