Is This vulnerability exploited in the wild?

No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

How severe is This vulnerability?

High severity, with a CVSS score of 7.5, published 30 October 2026.

Which products and versions are affected?

github.com/imgproxy/imgproxy/v3 (Go) >= 3.3.0, < 4.0.17, SEMVER:introduced=3.3.0,fixed=4.0.17; Imgproxy 3.3.x through 4.0.15.

Is there a fix for This vulnerability?

Yes. github.com/imgproxy/imgproxy/v3 (Go): upgrade to 4.0.17 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is This vulnerability attacked?

It is attacked over the network, in a hosted service.

Check whether you run github.com/imgproxy/imgproxy/v3 (Go) or Imgproxy at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

imgproxy out-of-bounds write in ICO loader BMP header

Q: Is there a fix for This vulnerability?

Yes. github.com/imgproxy/imgproxy/v3 (Go): upgrade to 4.0.17 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is This vulnerability attacked?

It is attacked over the network, in a hosted service.

Q: Am I affected?

Check whether you run github.com/imgproxy/imgproxy/v3 (Go) or Imgproxy at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Severity: high · CVSS 7.5 · Published 2026-10-30

imgproxy is an image processing service that handles ICO (Windows icon) files. A flaw in its ICO decoder allows an attacker to send a specially crafted image file that causes the server to crash and terminate the worker process handling the request. An unauthenticated attacker can trigger this denial of service repeatedly.

Technologies: github.com/imgproxy/imgproxy/v3 (Go), Imgproxy. Vendors: Go, Imgproxy.

Quick answers

Is This vulnerability exploited in the wild?: No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.
How severe is This vulnerability?: High severity, with a CVSS score of 7.5, published 30 October 2026.
Which products and versions are affected?: github.com/imgproxy/imgproxy/v3 (Go) >= 3.3.0, < 4.0.17, SEMVER:introduced=3.3.0,fixed=4.0.17; Imgproxy 3.3.x through 4.0.15.
Is there a fix for This vulnerability?: Yes. github.com/imgproxy/imgproxy/v3 (Go): upgrade to 4.0.17 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is This vulnerability attacked?: It is attacked over the network, in a hosted service.
Am I affected?: Check whether you run github.com/imgproxy/imgproxy/v3 (Go) or Imgproxy at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

github.com/imgproxy/imgproxy/v3 (Go): upgrade to 4.0.17 or later
```
go get github.com/imgproxy/imgproxy/v3@v4.0.17
```

Technical details

The vulnerability is an out-of-bounds heap write in vips/icoload.c during BMP header reconstruction. When processing an ICO entry with an undersized image data buffer, the loader reads unvalidated BITMAPINFOHEADER fields (num_colors, bpp, height) at fixed offsets that extend past the allocation, then writes a reconstructed 32-bit height value that corrupts the size field of the adjacent heap chunk. This corrupts the heap metadata such that the next free() deterministically triggers glibc's munmap_chunk() abort path, killing the imgproxy worker.

Affected products

imgproxy imgproxy 3.3.x through 4.0.15

Timeline

2026-10-30: disclosed

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