# CVE-2026-23876: Heap buffer overflow with attacker-controlled data in XBM parser

> Heap buffer overflow in ImageMagick's XBM parser allows attackers to execute arbitrary code or cause denial of service via crafted images.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 Jan 2026
- **Updated:** 15 Jul 2026
- **Also known as:** CLSA-2026-1770802828, CLSA-2026-1770820858, CLSA-2026-1770903151, CLSA-2026-1770909956, CLSA-2026-1770910304, DEBIAN-CVE-2026-23876, ECHO-55f4-7afa-d9c9, GHSA-r49w-jqq3-3gx8, JLSEC-2026-936, MINI-vhfq-x6vg-ch8j, UBUNTU-CVE-2026-23876, USN-8021-1

## What is CVE-2026-23876?

CVE-2026-23876 is a high-severity memory corruption vulnerability in Imagemagick Imagemagick, published on 20 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to versions 7.1.2-13 and 6.9.13-38, a heap buffer overflow vulnerability in the XBM image decoder (ReadXBMImage) allows an attacker to write controlled data past the allocated heap buffer when processing a maliciously crafted image file. Any operation that reads or identifies an image can trigger the overflow, making it exploitable via common image upload and processing pipelines. Versions 7.1.2-13 and 6.9.13-38 fix the issue.

Weakness: CWE-787 (Out-of-bounds Write), CWE-190 (Integer Overflow or Wraparound), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-23876?

It affects 1 product.


Products: Imagemagick Imagemagick.

## How do I fix CVE-2026-23876?

Upgrade to a fixed version.

## Is CVE-2026-23876 being exploited?

There is no known exploitation of CVE-2026-23876 in the wild and no public exploit code.

## Other vulnerabilities in Imagemagick Imagemagick

- [CVE-2019-19952](https://insights.sbomify.com/CVE-2019-19952/): Use after free in n/a (critical 9.8)
- [CVE-2018-16328](https://insights.sbomify.com/CVE-2018-16328/): Null dereference in n/a (critical 9.8)
- [CVE-2018-16329](https://insights.sbomify.com/CVE-2018-16329/): Null dereference in n/a (critical 9.8)
- [CVE-2017-18210](https://insights.sbomify.com/CVE-2017-18210/): Null dereference in n/a (critical 9.8)
- [CVE-2017-14138](https://insights.sbomify.com/CVE-2017-14138/): Denial of service in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23876 and fix it if it is affected.

What it is: CVE-2026-23876 is a high-severity memory corruption vulnerability in Imagemagick Imagemagick, published on 20 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-23876 in the wild and no public exploit code.

Affected product: Imagemagick Imagemagick. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-23876/ (Markdown: https://insights.sbomify.com/CVE-2026-23876/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23876
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23876
- OSV: https://osv.dev/vulnerability/CVE-2026-23876

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-23876/
Summaries are generated and may contain mistakes; the official description above is the record.