{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63276","assignerOrgId":"4fe7d05b-1353-44cc-8b7a-1e416936dff2","state":"PUBLISHED","assignerShortName":"Document Fdn.","dateReserved":"2026-07-16T08:17:05.512Z","datePublished":"2026-09-22T11:10:32.057Z","dateUpdated":"2026-09-22T12:21:57.496Z"},"containers":{"cna":{"providerMetadata":{"orgId":"4fe7d05b-1353-44cc-8b7a-1e416936dff2","shortName":"Document Fdn.","dateUpdated":"2026-09-22T11:10:32.057Z"},"title":"Stack buffer overflow in CFF to Type 1 font conversion","datePublic":"2026-09-21T23:59:00.000Z","descriptions":[{"lang":"en","value":"LibreOffice converts CFF fonts to Type 1 when it subsets a font, which happens when a document is exported to PDF, and CFF fonts may be embedded in documents. A stack buffer overflow existed in that conversion. The converted operators were written into a fixed size buffer with no check that they still fit, so a glyph emitting many operators wrote past the end of the buffer. In fixed versions the remaining capacity is tracked and the conversion stops when it is used up.","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>LibreOffice converts CFF fonts to Type 1 when it subsets a font, which happens when a document is exported to PDF, and CFF fonts may be embedded in documents.</p><p>A stack buffer overflow existed in that conversion. The converted operators were written into a fixed size buffer with no check that they still fit, so a glyph emitting many operators wrote past the end of the buffer.</p><p>In fixed versions the remaining capacity is tracked and the conversion stops when it is used up.</p>"}]}],"affected":[{"vendor":"The Document Foundation","product":"LibreOffice","defaultStatus":"unknown","versions":[{"status":"affected","version":"26.2","lessThan":"< 26.2.5","versionType":"26.2 series"}]}],"credits":[{"lang":"en","type":"finder","value":"Claude, found by Anthropic using agents to study the security of open-source projects"},{"lang":"en","type":"analyst","value":"Ada Logics, validating and reporting"},{"lang":"en","type":"remediation developer","value":"Caolán McNamara of Collabora Productivity"}],"problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-787","description":"CWE-787 Out-of-bounds Write","type":"CWE"}]}],"impacts":[{"capecId":"CAPEC-44","descriptions":[{"lang":"en","value":"CAPEC-44 Overflow Binary Resource File"}]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"LOCAL","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"PROOF_OF_CONCEPT","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"MEDIUM","baseScore":5.4,"vectorString":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:P"}}],"references":[{"url":"https://www.libreoffice.org/about-us/security/advisories/cve-2026-63276"}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"Vulnogram 1.0.2"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-22T12:21:19.661928Z","id":"CVE-2026-63276","options":[{"Exploitation":"none"},{"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":"2026-09-22T12:21:57.496Z"}}]}}