CVE-2026-59926

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{"bugzilla": {"description": "mistune: Mistune: Cross-Site Scripting via unescaped HTML class attribute in Admonition directive", "id": "2498149", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2498149"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.4", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N", "status": "draft"}, "cwe": "CWE-79", "details": ["Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, render_admonition() in src/mistune/directives/admonition.py concatenates the Admonition directive :class: option into the HTML class attribute without escaping, allowing attribute injection and cross-site scripting even when HTMLRenderer escape mode is enabled. This issue is fixed in version 3.2.1.", "A flaw was found in Mistune, a Python Markdown parser. The `render_admonition()` function in the Admonition directive concatenates user-controlled input into the HTML class attribute without proper escaping. This vulnerability allows for attribute injection and Cross-Site Scripting (XSS) attacks, even when the HTMLRenderer escape mode is enabled. A remote attacker could exploit this by providing specially crafted input, leading to the execution of arbitrary script code in the user's browser."], "mitigation": {"lang": "en:us", "value": "To mitigate this issue, avoid processing untrusted or unvalidated Markdown content with affected versions of the Mistune library. Implement robust input validation and sanitization for any user-provided Markdown before rendering to prevent the injection of malicious attributes or scripts."}, "name": "CVE-2026-59926", "package_state": [{"cpe": "cpe:/a:redhat:migration_toolkit_applications:8", "fix_state": "Fix deferred", "package_name": "mta/mta-solution-server-rhel9", "product_name": "Migration Toolkit for Applications 8"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-pipeline-runtime-datascience-cpu-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-pipeline-runtime-minimal-cpu-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-pipeline-runtime-pytorch-cuda-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-pipeline-runtime-pytorch-llmcompressor-cuda-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-pipeline-runtime-pytorch-rocm-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-pipeline-runtime-tensorflow-cuda-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-pipeline-runtime-tensorflow-rocm-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-th06-cpu-torch210-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-th06-cpu-torch291-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-th06-cuda130-torch210-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-th06-cuda130-torch291-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-th06-rocm64-torch291-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-workbench-jupyter-datascience-cpu-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-workbench-jupyter-minimal-cpu-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-workbench-jupyter-minimal-cuda-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-workbench-jupyter-minimal-rocm-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-workbench-jupyter-pytorch-cuda-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-workbench-jupyter-pytorch-rocm-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-workbench-jupyter-tensorflow-cuda-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-workbench-jupyter-tensorflow-rocm-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Under investigation", "package_name": "rhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "python-mistune", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:satellite:6", "fix_state": "Under investigation", "package_name": "satellite/iop-advisor-engine-rhel9", "product_name": "Red Hat Satellite 6"}], "public_date": "2026-07-08T16:16:15Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-59926\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-59926\nhttps://github.com/lepture/mistune/commit/a3cb6e5655308797e8be021d6c7b5bab13cbace2\nhttps://github.com/lepture/mistune/releases/tag/v3.2.1\nhttps://github.com/lepture/mistune/security/advisories/GHSA-g97x-gvcm-x72h"], "statement": "This Moderate flaw in the Mistune Markdown parser allows for Cross-Site Scripting (XSS) due to improper sanitization of user-controlled input within the Admonition directive's class attribute. An attacker could exploit this by providing specially crafted Markdown content, leading to the execution of arbitrary script code in a user's browser when the content is rendered. This vulnerability requires user interaction with malicious content for successful exploitation.", "threat_severity": "Moderate"}

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