PDFio < 1.6.5 Dangling Pointer via Dictionary String-Formatting
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.
CVE-2026-77220
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-77220
pdfio
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://github.com/michaelrsweet/pdfio",
"vendor": "michaelrsweet",
"product": "pdfio",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "1.6.5",
"versionType": "semver"
}
],
"packageURL": "pkg:github/michaelrsweet/pdfio",
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-77220
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #5529 · Revision 1
- Added to Heist Feed
- Publisher date