What is CVE-2026-23512?

CVE-2026-23512 is a high-severity vulnerability in Microsoft Windows, classified under Untrusted Search Path. CVSS score: 8.6/10. Published 2026-01-14.

How severe is CVE-2026-23512?

High severity. CVSS v3 base score is 8.6 out of 10.

Vulnerability in Microsoft Windows

CVE-2026-23512

SumatraPDF is a multi-format reader for Windows. In 3.5.2 and earlier, there is a Untrusted Search Path vulnerability when Advanced Options setting is trigger. The application executes notepad.exe without specifying an absolute path when using the Advanced Options setting. On Windows, this allows execution of a malicious notepad.exe placed in the application's installation directory, leading to arbitrary code execution.

Published 2026-01-14 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (11.5th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 11.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

Microsoft Windows
Sumatrapdfreader Sumatrapdf — versions <= 3.5.2

Weakness classification (CWE)

CWE-426 — Untrusted Search Path

References

github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-rqg5-gj63-x4mv (Exploit, Vendor Advisory)
github.com/sumatrapdfreader/sumatrapdf/commit/2762e02a8cd7cb779c934a44257aac56a… (Patch)

Frequently asked questions

What is CVE-2026-23512?: CVE-2026-23512 is a high-severity vulnerability in Microsoft Windows, classified under Untrusted Search Path. CVSS score: 8.6/10. Published 2026-01-14.
How severe is CVE-2026-23512?: High severity. CVSS v3 base score is 8.6 out of 10.