---
id: "CVE-2026-92454"
kind: "vulnerability"
aliases: ["CVE-2026-92454"]
title: "GUIX JPEG decoder: truncated markers read past buffer, zero sampling hangs"
severity: "medium"
cvss: 6.8
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["embedded", "guix", "image-decoding", "package"]
not_affected_if: ["no-untrusted-jpeg-input"]
published_at: "2026-10-20T15:17:36+00:00"
first_seen_at: "2026-10-23T21:57:20+00:00"
updated_at: "2026-10-25T03:44:43+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-92454", "first_seen_at": "2026-10-23T21:57:20+00:00"}]
---

# GUIX JPEG decoder: truncated markers read past buffer, zero sampling hangs

The GUIX software JPEG decoder reads four kinds of marker segment without checking their length, so a truncated segment is read past the end of the image buffer. A zero chroma sampling factor also makes the block decode loop never finish, which can hang the process.

_Summary, check and fix written by a model from the sources; labelled as such._

## Timeline

- 2026-10-23T21:57:20+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-92454

## From the sources

The GUIX software JPEG decoder reads four kinds of marker segment without checking that each is long enough to hold what it reads. A truncated segment is therefore read past the end of the caller's image buffer. Separately, a zero chroma sampling factor makes the block decode loop non-terminating. Both reproduce in the default configuration, in which `GX_SOFTWARE_DECODER_SUPPORT` is enabled.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_