CVE-2026-23512: SumatraPDF is a multi-format reader for Windows

Q: How do I fix CVE-2026-23512?

sumatrapdf: upgrade to newer than 3.5.2. Exact commands for each OS are on this page.

Q: Is CVE-2026-23512 being exploited?

CVE-2026-23512 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-23512 affect?

CVE-2026-23512 affects sumatrapdf. Severity is high (CVSS 8.6). 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 us

Q: How urgent is CVE-2026-23512?

Priority 38/100. High severity; Public exploit reference

Routine

HIGH 8.6UPGRADE

CVE-2026-23512 is a high-severity flaw (CVSS 8.6) affecting sumatrapdf. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	8.6 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 87%)
CISA exploited list	No
Weakness	CWE-426
Published	2026-01-14
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: sumatrapdfreader

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-01-14 21:15 UTCPublished CVE record published
2026-06-17 10:21 UTCUpdated Record last modified

sumatrapdfreader sumatrapdf UPGRADE

Affected: <= 3.5.2

Fixed in: newer than 3.5.2

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy sumatrapdf || rpm -q sumatrapdf || sumatrapdf --version

2. UPGRADE to newer than 3.5.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade sumatrapdf

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade sumatrapdf

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-23512?

sumatrapdf: upgrade to newer than 3.5.2. Exact commands for each OS are on this page.

Is CVE-2026-23512 being exploited?

CVE-2026-23512 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-23512 affect?

CVE-2026-23512 affects sumatrapdf. Severity is high (CVSS 8.6). 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 us

How urgent is CVE-2026-23512?

Priority 38/100. High severity; Public exploit reference

Software pages

Windows vulnerabilities

Related CVEs

CVE-2026-23951 MEDIUM 5.5 MITIGATE SumatraPDF is a multi-format reader for Windows
CVE-2025-57248 HIGH 7.3 DOWNGRADE A null pointer dereference vulnerability was discovered in SumatraPDF 3.5.2 during the processing of a crafted

References

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