Gzip Decompression Bomb via Content-Encoding Header
Summary
| CVE | CVE-2026-5438 |
|---|---|
| State | PUBLISHED |
| Assigner | certcc |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-09 15:16:15 UTC |
| Updated | 2026-04-14 17:16:53 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 7.5 HIGH from ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.000170000 probability, percentile 0.038940000 (date 2026-04-14)
Problem Types: CWE-770 Allocation of Resources Without Limits or Throttling
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | ADP | DECLARED | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Orthanc | DICOM Server | affected 1.12.10 custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| kb.cert.org/vuls/id/536588 | [email protected] | kb.cert.org | |
| www.orthanc-server.com | [email protected] | www.orthanc-server.com | |
| www.machinespirits.de | [email protected] | www.machinespirits.de | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.