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.
History

Fri, 21 Aug 2026 21:15:00 +0000

Type Values Removed Values Added
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.
Title PDFio < 1.6.5 Dangling Pointer via Dictionary String-Formatting
Weaknesses CWE-825
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N'}

cvssV4_0

{'score': 7.1, '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-21T20:54:34.762Z

Reserved: 2026-08-20T18:25:46.943Z

Link: CVE-2026-77220

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-21T21:17:06.737

Modified: 2026-08-21T21:17:06.737

Link: CVE-2026-77220

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-21T22:45:04Z