CVE-2026-5438

Name: CVE-2026-5438
Creator: NVD / NIST
Published: 2026-04-09T15:16:15.327+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.48%

Last modified Jun 17, 2026

CVE-2026-5438 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 0.48% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.48%

38.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-770

Affected Software

Vendor	Product	Versions
Orthanc-Server	Orthanc	< 1.12.11

References

https://kb.cert.org/vuls/id/536588Third Party Advisory, VDB Entry
https://www.machinespirits.de/Not Applicable
https://www.orthanc-server.com/Product

Timeline

Published: Apr 9, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-5438?

How severe is CVE-2026-5438?

CVE-2026-5438 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.48% probability of exploitation in the next 30 days.

How do I fix CVE-2026-5438?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-5438?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST