{"affected":[{"defaultStatus":"affected","ecosystem":"github","packageName":"michaelrsweet/pdfio","product":"pdfio","source":"CNA: VulnCheck","vendor":"michaelrsweet","versions":[{"lessThan":"1.6.5","status":"affected","version":"0","versionType":"semver"}]}],"cveId":"CVE-2026-77220","cwes":["CWE-825"],"description":"PDFio before 1.6.5 contains a dangling pointer vulnerability in the dictionary string-formatting function that stores a pointer to a stack-local buffer in the document dictionary without copying the string value. In multi-threaded or pooled-request environments, attackers or concurrent users can trigger stack memory reuse across requests, causing cross-tenant document content corruption by silently overwriting one caller's dictionary string values with another caller's data.","epss":{"date":"2026-11-08","percentile":0.36723,"score":0.00421},"exploits":[],"kev":null,"metrics":[{"score":7.1,"severity":"high","source":"CNA: VulnCheck","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0"},{"score":6.5,"severity":"medium","source":"CNA: VulnCheck","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}],"modifiedAt":1794146936091,"publishedAt":1787345674762,"references":[{"source":"CNA: VulnCheck","tags":["release-notes"],"url":"https://github.com/michaelrsweet/pdfio/releases/tag/v1.6.5"},{"source":"CNA: VulnCheck","tags":["patch"],"url":"https://github.com/michaelrsweet/pdfio/commit/22b9afc800c5833f9e851e35938972bd4c76a357"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/pdfio-dangling-pointer-via-dictionary-string-formatting"}],"remediation":[{"kind":"fix","source":"CNA: VulnCheck","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/michaelrsweet/pdfio/commit/22b9afc800c5833f9e851e35938972bd4c76a357"}],"revision":"7a8a859ca255696114407ed26cd0ade67bbb2a559b37936660ea09190a608458","sources":[{"modifiedAt":1794146936091,"name":"CNA: VulnCheck","retrievedAt":1794151362545,"url":"https://www.cve.org/CVERecord?id=CVE-2026-77220"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1794151367164,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-77220"}],"ssvc":{"assessedAt":1787600429774,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"PDFio < 1.6.5 Dangling Pointer via Dictionary String-Formatting","updatedAt":1794151367164}