CVE-2026-25961
published 2026-02-09CVE-2026-25961: SumatraPDF is a multi-format reader for Windows. In 3.5.0 through 3.5.2, SumatraPDF's update mechanism disables TLS hostname verification…
PriorityP355high7.5CVSS 3.1
AVNACHPRNUIRSUCHIHAH
EXPLOIT
EPSS
0.45%
35.5th percentile
SumatraPDF is a multi-format reader for Windows. In 3.5.0 through 3.5.2, SumatraPDF's update mechanism disables TLS hostname verification (INTERNET_FLAG_IGNORE_CERT_CN_INVALID) and executes installers without signature checks. A network attacker with any valid TLS certificate (e.g., Let's Encrypt) can intercept the update check request, inject a malicious installer URL, and achieve arbitrary code execution.
Affected
2 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| sumatrapdfreader | sumatrapdf | — | — |
| sumatrapdfreader | sumatrapdf | 3.5 – 3.5.2 | — |
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No advisories linked to this vulnerability.
No detection rules found.
Wiz
CVE-2026-23951 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 8.6
CVE-2026-23951 [HIGH] CVE-2026-23951 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-23951 :
SumatraPDF vulnerability analysis and mitigation
SumatraPDF is a multi-format reader for Windows. All versions contain an off-by-one error in the validation code that only triggers with exactly 2 records, causing an integer underflow in the size calculation. This bug exists in PalmDbReader::GetRecord when opening a crafted Mobi file, resulting in an out-of-bounds heap read that crashes the app. There are no published fixes at the time of publication.
Source : NVD
## 5.5
Score
Published January 22, 2026
Severity MEDIUM
CNA Score 5.5
Affected Technologies
SumatraPDF
Has Public Exploit Yes
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 0.6
Exploitation Probability (EPSS) N/A
Affected pac
Wiz
CVE-2026-23512 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 8.6
CVE-2026-23512 [HIGH] CVE-2026-23512 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-23512 :
SumatraPDF vulnerability analysis and mitigation
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.
Source : NVD
## 7.8
Score
Published January 14, 2026
Severity HIGH
CNA Score 8.6
Affected Technologies
SumatraPDF
Has Public Exploit Yes
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 5.4
Exploitation Probability (EPSS) N
Wiz
CVE-2026-25961 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 8.6
CVE-2026-25961 [HIGH] CVE-2026-25961 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-25961 :
SumatraPDF vulnerability analysis and mitigation
SumatraPDF is a multi-format reader for Windows. In 3.5.0 through 3.5.2, SumatraPDF's update mechanism disables TLS hostname verification (INTERNET_FLAG_IGNORE_CERT_CN_INVALID) and executes installers without signature checks. A network attacker with any valid TLS certificate (e.g., Let's Encrypt) can intercept the update check request, inject a malicious installer URL, and achieve arbitrary code execution.
Source : NVD
## 7.5
Score
Published February 9, 2026
Severity HIGH
CNA Score 7.5
Affected Technologies
SumatraPDF
Has Public Exploit Yes
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 5.8
Exploitation Probability (EPSS) N/A
Affected
Wiz
CVE-2026-25920 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 8.6
CVE-2026-25920 [HIGH] CVE-2026-25920 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-25920 :
SumatraPDF vulnerability analysis and mitigation
SumatraPDF is a multi-format reader for Windows. In 3.5.2 and earlier, a heap out-of-bounds read vulnerability exists in SumatraPDF's MOBI HuffDic decompressor. The bounds check in AddCdicData() only validates half the range that DecodeOne() actually accesses. Opening a crafted .mobi file can read nearly (1 << codeLength) bytes beyond the CDIC dictionary buffer, leading to a crash.
Source : NVD
## 5.5
Score
Published February 9, 2026
Severity MEDIUM
CNA Score 5.5
Affected Technologies
SumatraPDF
Has Public Exploit Yes
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 6.4
Exploitation Probability (EPSS) N/A
Affected packages and libraries
Wiz
CVE-2026-25880 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 8.6
CVE-2026-25880 [HIGH] CVE-2026-25880 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-25880 :
SumatraPDF vulnerability analysis and mitigation
SumatraPDF is a multi-format reader for Windows. In 3.5.2 and earlier, the PDF reader allows execution of a malicious binary (explorer.exe) located in the same directory as the opened PDF when the user clicks File → “Show in folder”. This behavior leads to arbitrary code execution on the victim’s system with the privileges of the current user, without any warning or user interaction beyond the menu click.
Source : NVD
## 7.8
Score
Published February 9, 2026
Severity HIGH
CNA Score 7.8
Affected Technologies
SumatraPDF
Has Public Exploit Yes
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 4.7
Exploitation Probability (EPSS) N/A
Affected pa
2026-02-09
Published