---
id: CVE-2026-123615
title: imgproxy before 4.0.17 Out-of-Bounds Write in ICO Loader
summary: >-
  imgproxy 3.3.0 before 4.0.17 contains an out-of-bounds heap read and write in
  the ICO loader's BMP header reconstruction (vips_foreign_load_ico_header in
  vips/icoload.c) when an ICO entry declares a tiny data size, causing
  unvalidated he…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-787
vendor: imgproxy
product: imgproxy
affected:
  - imgproxy >= 3.3.0 < 4.0.17
published: '2026-11-08'
updated: '2026-11-08'
sourceUpdated: '2026-11-08T01:38:39.703Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-123615'
references:
  - url: >-
      https://github.com/imgproxy/imgproxy/security/advisories/GHSA-494m-4556-wf5p
    label: GitHub Security Advisory (GHSA-494m-4556-wf5p)
  - url: >-
      https://www.vulncheck.com/advisories/imgproxy-before-4.0.17-out-of-bounds-write-in-ico-loader
    label: >-
      VulnCheck Advisory: imgproxy before 4.0.17 Out-of-Bounds Write in ICO
      Loader
tags:
  - cve.org
ingestedAt: '2026-11-08T02:43:18.636Z'
---

## Overview

imgproxy 3.3.0 before 4.0.17 contains an out-of-bounds heap read and write in the ICO loader's BMP header reconstruction (vips_foreign_load_ico_header in vips/icoload.c) when an ICO entry declares a tiny data size, causing unvalidated header fields to be read and written past the allocated buffer. Unauthenticated remote attackers can supply a crafted ICO image to corrupt adjacent heap chunk metadata, triggering a glibc abort that crashes the worker.

## Affected

- `imgproxy >= 3.3.0 < 4.0.17`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.