SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-26233

Attackers could exploit this issue for a Denial of Service (DoS) or possibly to achieve code execution.

HIGH 7.8EPSS 1.06%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.06%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

FastStone Image Viewer <= 7.5 is affected by a user mode write access violation near NULL at 0x005bdfcb, 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.

CVSS 3.1
7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
1.06% probability · 64th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-787
Affected
faststone/image viewer
Source
cve@mitre.org
EPSS trend
0%3%5%26 October 2026: 1.06%26 October 202626 October 2026

EPSS 1.1% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.