CVE-2026-5438: high-severity vulnerability in Orthanc DICOM Server
Gzip Decompression Bomb via Content-Encoding Header
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.5%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
Orthanc · DICOM ServerRelated CVEs — Orthanc DICOM Server
In the same product, most dangerous first.
CVE-2026-5445CRITICALOut-of-Bounds Read in DicomImageDecoder (DecodeLookupTable)EPSS 0.7%CVE-2026-5437HIGHOut-of-Bounds Read in DicomStreamReaderEPSS 0.7%CVE-2026-5442CRITICALHeap Buffer Overflow in DICOM Image Decoder via VR UL DimensionsEPSS 0.6%CVE-2026-5440HIGHMemory Exhaustion via Unbounded Content-LengthEPSS 0.6%CVE-2026-5443CRITICALHeap Buffer Overflow in DICOM Image Decoder (Palette Color Decode)EPSS 0.6%CVE-2026-87020HIGHOrthanc DICOM Server Integer Overflow or WraparoundEPSS 0.6%