# Out-of-bounds Write in SixLabors ImageSharp

Advisory record · `GHSA-2cmq-823j-5qj8`

- **Identifiers:** `GHSA-2cmq-823j-5qj8` · `CVE-2025-27598`
- **State:** Confirmed
- **Severity:** CVSS 7.5 High
- **Critical:** No
- **Weakness (CWE):** [CWE-787](https://cwe.mitre.org/data/definitions/787.html)
- **Tags:** [Memory corruption](https://agentprime.io/advisories/tag/memory-corruption.md)
- **Published:** 6 Mar 2025
- **Updated:** 7 Mar 2025
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 6 Mar 2025, 22:23 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `SixLabors.ImageSharp` (NuGet): affected `>=3.0.0, <3.1.7 || <2.1.10`; fixed in `3.1.7`, `2.1.10`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> SixLabors.ImageSharp versions before 2.1.10, and from 3.0.0 before 3.1.7, are affected by an out-of-bounds write in the GIF decoder. An attacker can exploit it by supplying a specially crafted GIF file, causing a crash that may lead to denial of service. Upgrade to version 3.1.7 or 2.1.10; no workaround is listed.

Written 9 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 7.5 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0057, the 47th percentile, on 11 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 6 Mar 2025, 19:42 UTC: [Published by the maintainers as a GitHub repository advisory](https://github.com/SixLabors/ImageSharp/security/advisories/GHSA-2cmq-823j-5qj8)
- 31 Oct 2026, 15:22 UTC: First seen by agentprime
- 31 Oct 2026, 15:22 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-2cmq-823j-5qj8)

## Sources

- [GitHub Advisory Database: GHSA-2cmq-823j-5qj8](https://github.com/advisories/GHSA-2cmq-823j-5qj8)
- [OSV: GHSA-2cmq-823j-5qj8](https://osv.dev/vulnerability/GHSA-2cmq-823j-5qj8)
- <https://github.com/SixLabors/ImageSharp/security/advisories/GHSA-2cmq-823j-5qj8>
- <https://nvd.nist.gov/vuln/detail/CVE-2025-27598>
- <https://github.com/SixLabors/ImageSharp/issues/2859>
- <https://github.com/SixLabors/ImageSharp/pull/2890>
- <https://github.com/SixLabors/ImageSharp>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-2cmq-823j-5qj8>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-2cmq-823j-5qj8/>. Everything for agents: <https://agentprime.io/llms.txt>.