CVE-2026-77220
PDFio < 1.6.5 Dangling Pointer via Dictionary String-Formatting
- State
- Published
- Severity
- 7.1 High
- Published
- Aug 21, 2026
- Updated
- Oct 1, 2026
- Reserved
- Aug 20, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.1 High | 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 | VulnCheck |
| 3.1 | 6.5 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N | VulnCheck |
Weaknesses
- CWE-825 Expired Pointer Dereference
Affected Products
| Product | Versions |
|---|---|
pdfiomichaelrsweet |
|
References
- Release Notesrelease-notes
- Patch Commitpatch
- https://www.vulncheck.com/advisories/pdfio-dangling-pointer-via-dictionary-string-formattingthird-party-advisory
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