Is CVE-2021-26234 actively exploited?

No active exploitation of CVE-2021-26234 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-26234 be exploited remotely?

No. CVE-2021-26234 requires local access to exploit.

What is the CVSS score of CVE-2021-26234?

CVE-2021-26234 has a CVSS score of 7.8 (HIGH).

HOME VULNERABILITIESCVE-2021-26234

HIGH

CVE-2021-26234

CWE-787Published: March 18, 2021· Updated: Jun 17, 2026

7.8

CVSS v3.1

Official Description

FastStone Image Viewer <= 7.5 is affected by a user mode write access violation at 0x00402d8a, triggered when a user opens or views a malformed CUR file that is mishandled by FSViewer.exe. Attackers could exploit this issue for a Denial of Service (DoS) or possibly to achieve code execution.

NVD Source

Technical Analysis

CVE-2021-26234 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.8.

From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.