CVE-2021-26236

What it is

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.

At a glance

Exploitability

Can be exploited locally on the machine without logging in, but needs a user to act. High risk of data exposure, data tampering, service disruption.

Exploit odds

2.0% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2021-01-25 00:00 UTC ReservedThe CVE id was reserved by its CNA
2. 2021-03-18 13:15 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-06-17 03:42 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 2.0% in the next 30 days (EPSS).
• Severity: 7.8 HIGH (CVSS).
• Fix: none linked yet, which raises it.

Details

Published

2021-03-18 13:15 UTC

Last modified

2026-06-17 03:42 UTC

Exploit probability

2.0% · EPSS, next 30 days

Weakness

CWE-787 · Out-of-bounds write

Record status

Modified

Affected

• Faststone Image Viewer ≤ 7.5

Attack profile CVSS 3.1 · 7.8

Attack vector

Local

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-26236.md and follow it. Check whether this project is affected by CVE-2021-26236. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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