CVE-2021-26236
CVSS v3
7.8
HIGH
EPSS Score
2.0 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
FastStone Image Viewer v.<= 7.5 is affected by a Stack-based Buffer Overflow at 0x005BDF49, affecting the CUR file parsing functionality (BITMAPINFOHEADER Structure, 'BitCount' file format field), that will end up corrupting the Structure Exception Handler (SEH). Attackers could exploit this issue to achieve code execution when a user opens or views a malformed/specially crafted CUR file.
Technical details
- Published
- 2021-03-18
Frequently asked questions
What is CVE-2021-26236?
FastStone Image Viewer v.<= 7.5 is affected by a Stack-based Buffer Overflow at 0x005BDF49, affecting the CUR file parsing functionality (BITMAPINFOHEADER Structure, 'BitCount' file format field), that will end up corrupting the Structure Exception Handler (SEH). Attackers could exploit this issue to achieve code execution when a user opens or views a malformed/specially crafted CUR file.
Is CVE-2021-26236 actively exploited?
Active exploitation of CVE-2021-26236 has not been confirmed. Its EPSS score was 2.0% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-26236?
CVE-2021-26236 has a CVSS v3 base score of 7.8 (HIGH severity).
Is CVE-2021-26236 affecting your environment?
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