Vulnerability · Published Apr 9, 2026 · Assigned by certcc
CVE-2026-5440Memory Exhaustion via Unbounded Content-Length
High 7.5
In plain English
A high-severity security flaw in DICOM Server from Orthanc. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
A memory exhaustion vulnerability exists in the HTTP server due to unbounded use of the `Content-Length` header. The server allocates memory directly based on the attacker supplied header value without enforcing an upper limit. A crafted HTTP request containing an extremely large `Content-Length` value can trigger excessive memory allocation and server termination, even without sending a request body.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | orthanc | no fix listed | DEBIAN-CVE-2026-5440 |
| Debian:13 | orthanc | no fix listed | DEBIAN-CVE-2026-5440 |
| Debian:14 | orthanc | 1.12.10+dfsg-4 | DEBIAN-CVE-2026-5440 |
| Ubuntu:22.04:LTS | orthanc | no fix listed | UBUNTU-CVE-2026-5440 |
| Ubuntu:24.04:LTS | orthanc | no fix listed | UBUNTU-CVE-2026-5440 |
| Ubuntu:25.10 | orthanc | no fix listed | UBUNTU-CVE-2026-5440 |
| Ubuntu:26.04:LTS | orthanc | no fix listed | UBUNTU-CVE-2026-5440 |
| Ubuntu:26.10 | orthanc | no fix listed | UBUNTU-CVE-2026-5440 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Orthanc | DICOM Server | 0 – through 1.12.10 |