PatchTheCVECVE-2026-5440: A memory exhaustion vulnerability exists in the HTTP server due to unbounded use of the `Content-Length` heade
CVE-2026-5440 is a high-severity flaw (CVSS 7.5) affecting orthanc. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- High severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.5 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.6% (top 53%) |
| CISA exploited list | No |
| Weakness | CWE-770 |
| Published | 2026-04-09 |
| Last modified | 2026-10-26 |
Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-5440?
orthanc: upgrade to 1.12.11. Exact commands for each OS are on this page.
Is CVE-2026-5440 being exploited?
CVE-2026-5440 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-5440 affect?
CVE-2026-5440 affects orthanc. Severity is high (CVSS 7.5). 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 H
How urgent is CVE-2026-5440?
Priority 43/100. High severity; Remotely exploitable, no login, no user action
Related CVEs
- CVE-2026-5442 CRITICAL 9.8 UPGRADE A heap buffer overflow vulnerability exists in the DICOM image decoder
- CVE-2026-5443 CRITICAL 9.8 UPGRADE A heap buffer overflow vulnerability exists during the decoding of `PALETTE COLOR` DICOM images
- CVE-2026-5445 CRITICAL 9.1 UPGRADE An out-of-bounds read vulnerability exists in the `DecodeLookupTable` function within `DicomImageDecoder.cpp`
- CVE-2026-5437 HIGH 7.5 UPGRADE An out-of-bounds read vulnerability exists in `DicomStreamReader` during DICOM meta-header parsing
- CVE-2026-5439 HIGH 7.5 UPGRADE A memory exhaustion vulnerability exists in ZIP archive processing