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Fencer Vulns
high 7.8

CVE-2021-26237 json

FastStone Image Viewer <= 7.5 is affected by a user mode write access violation at 0x00402d7d, triggered when a user opens or views a malfo…

published 2021-03-18 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-13054

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.7%
EPSS 2.7% chance of exploitation in 30 days, percentile 86%
public exploits
0
none known

Summary

FastStone Image Viewer <= 7.5 is affected by a user mode write access violation at 0x00402d7d, 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.

Exploit prediction

2.73% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.