VDB-342292 · CVE-2026-23951 · GHSA-hj4w-c5x8-p2hv

SumatraPDF up to 3.5.2rel on Windows Mobi File PalmDbReader::GetRecord out-of-bounds

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
4.9	$0-$5k	0.00

Summaryinfo

A vulnerability was found in SumatraPDF up to 3.5.2rel on Windows. It has been declared as problematic. Impacted is the function PalmDbReader::GetRecord of the component Mobi File Handler. Executing a manipulation can lead to out-of-bounds. This vulnerability is tracked as CVE-2026-23951. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability has been found in SumatraPDF up to 3.5.2rel on Windows and classified as problematic. This vulnerability affects the function PalmDbReader::GetRecord of the component Mobi File Handler. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-23951 since 01/19/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-4205). Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

SumatraPDF

Version

3.5.2rel

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.9
VulDB Meta Temp Score: 4.9

VulDB Base Score: 4.3
VulDB Temp Score: 4.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

01/19/2026 CVE reserved
01/22/2026 +3 days Advisory disclosed
01/22/2026 +0 days VulDB entry created
01/23/2026 +1 days VulDB entry last update

Sourcesinfo

Advisory: GHSA-hj4w-c5x8-p2hv
Status: Confirmed

CVE: CVE-2026-23951 (🔒)
GCVE (CVE): GCVE-0-2026-23951
GCVE (VulDB): GCVE-100-342292
EUVD: 🔒

Entryinfo

Created: 01/22/2026 08:11
Updated: 01/23/2026 07:13
Changes: 01/22/2026 08:11 (64), 01/23/2026 07:13 (1)
Complete: 🔍
Cache ID: 216::103