{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-44899","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-05-07T21:50:33.546Z","datePublished":"2026-05-26T20:36:40.461Z","dateUpdated":"2026-05-27T13:31:02.744Z"},"containers":{"cna":{"title":"Mistune Image Directive CSS Injection Vulnerability","problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"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"}}],"references":[{"name":"https://github.com/lepture/mistune/security/advisories/GHSA-ccfx-mfmx-2fx9","tags":["x_refsource_CONFIRM"],"url":"https://github.com/lepture/mistune/security/advisories/GHSA-ccfx-mfmx-2fx9"},{"name":"https://github.com/lepture/mistune/releases/tag/v3.2.1","tags":["x_refsource_MISC"],"url":"https://github.com/lepture/mistune/releases/tag/v3.2.1"}],"affected":[{"vendor":"lepture","product":"mistune","versions":[{"version":"< 3.2.1","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-05-26T20:36:40.461Z"},"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."}],"source":{"advisory":"GHSA-ccfx-mfmx-2fx9","discovery":"UNKNOWN"}},"adp":[{"references":[{"url":"https://github.com/lepture/mistune/security/advisories/GHSA-ccfx-mfmx-2fx9","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-27T13:28:35.879099Z","id":"CVE-2026-44899","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-05-27T13:31:02.744Z"}}]}}