PT-2026-7172 · Unknown · Sumatrapdf

Haaeein · Published 2026-02-09 · Updated 2026-02-10 · CVE-2026-25961

Positive Technologies (AI Summary)

CVSS v2.0

7.6

High

Base vector

AV:N/AC:H/Au:N/C:C/I:C/A:C

Name of the Vulnerable Software and Affected Versions SumatraPDF versions 3.5.0 through 3.5.2

Description SumatraPDF’s update process has a flaw where TLS hostname verification is disabled (INTERNET FLAG IGNORE CERT CN INVALID) and installers are executed without signature verification. This allows a network attacker possessing a valid TLS certificate, such as one from Let's Encrypt, to intercept the update check, inject a malicious installer URL, and potentially execute arbitrary code.

Recommendations Update to a version beyond 3.5.2.

Exploit

Fix

Improper Certificate Validation

Weakness Enumeration

CWE-494

CWE-295

Related Identifiers

BDU:2026-01951

CVE-2026-25961

GHSA-XPM2-RR5M-X96Q

Affected Products

Sumatrapdf

References · 7

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25961.json · Exploit
• https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-xpm2-rr5m-x96q · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-25961 · Security Note
• https://osv.dev/vulnerability/CVE-2026-25961 · Vendor Advisory
• https://bdu.fstec.ru/vul/2026-01951 · Security Note
• https://t.me/CVEtracker/44240 · Telegram Post
• https://twitter.com/VulmonFeeds/status/2021106769800430008 · Twitter Post