CVE-2026-44899

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{"affected": [{"affectedData": [{"product": "mistune", "vendor": "lepture", "versions": [{"status": "affected", "version": "< 3.2.1"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:mistune_project:mistune:*:*:*:*:*:*:*:*", "matchCriteriaId": "A91629D7-7A30-4A3F-B1AD-17FE21D59820", "versionEndExcluding": "3.2.1", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, the Image directive plugin validates the :width: and :height: options with a regex compiled as _num_re = re.compile(r\"^\\d+(?:\\.\\d*)?\"). When the validated value is not a plain integer, render_block_image() inserts it directly into a style=\"width:...;\" or style=\"height:...;\" attribute. Because the value was accepted by the prefix-only regex, any CSS after the leading digits reaches the style= attribute verbatim and without escaping. This vulnerability is fixed in 3.2.1."}, {"lang": "es", "value": "Mistune es un analizador de Markdown de Python con renderizadores y plugins. Antes de la versi\u00f3n 3.2.1, el plugin de la directiva Image valida las opciones :width: y :height: con una expresi\u00f3n regular compilada como _num_re = re.compile(r\"^\\d+(?:\\.\\d)?\"). Cuando el valor validado no es un n\u00famero entero simple, render_block_image() lo inserta directamente en un atributo style=\"width:...;\" o style=\"height:...;\". Debido a que el valor fue aceptado por la expresi\u00f3n regular de solo prefijo, cualquier CSS despu\u00e9s de los d\u00edgitos iniciales llega al atributo style= textualmente y sin escape. Esta vulnerabilidad est\u00e1 corregida en la versi\u00f3n 3.2.1."}], "id": "CVE-2026-44899", "lastModified": "2026-07-24T11:10:00.170", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.7, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.1, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 2.7, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-44899", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-05-27T13:28:35.879099Z", "version": "2.0.3"}}]}, "published": "2026-05-26T21:16:39.953", "references": [{"source": "security-advisories@github.com", "tags": ["Product", "Release Notes"], "url": "https://github.com/lepture/mistune/releases/tag/v3.2.1"}, {"source": "security-advisories@github.com", "tags": ["Exploit", "Vendor Advisory"], "url": "https://github.com/lepture/mistune/security/advisories/GHSA-ccfx-mfmx-2fx9"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"], "url": "https://github.com/lepture/mistune/security/advisories/GHSA-ccfx-mfmx-2fx9"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,3.2.1)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "mistune", "source": "cna", "vendor": "lepture"}, "product": "mistune", "vendor": "lepture"}], "created": "2026-05-26T22:45:06.253976+00:00", "updated": "2026-05-26T23:15:20.069796+00:00", "vendors": ["lepture", "lepture$PRODUCT$mistune"]}