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TI-2026-04761 Aliases CVE-2026-5438GHSA-7vj5-pm38-6wjv

Gzip Decompression Bomb via Content-Encoding Header

Priority LOW 39CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-770.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00493 42nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
OrthancDICOM Serverup to 1.12.10—No fix listedCNA
  • DICOM Server VendorOrthanc Affected up to 1.12.10 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:orthanc-server:orthanc:*:*:*:*:*:*:*:*before 1.12.11VulnerableOrthanc
  • cpe:2.3:a:orthanc-server:orthanc:*:*:*:*:*:*:*:* Versions before 1.12.11 Vulnerable ·Orthanc

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-5438
  2. 2026-10-03 Alias added: GHSA-7vj5-pm38-6wjv
  3. 2026-10-25 EPSS moved to the below the 50th percentile
  4. 2026-10-25 Priority changed: MEDIUM → LOW

References

Advisory 1

Other 2

  • TI-2025-00759 Orthanc Server Missing Authentication for Critical Function CVSS 4.0CRITICAL 9.2
  • TI-2026-04766 Heap Buffer Overflow in DICOM Image Decoder (Palette Color Decode) CVSS 3.1CRITICAL 9.8
  • TI-2026-04765 Heap Buffer Overflow in DICOM Image Decoder via VR UL Dimensions CVSS 3.1CRITICAL 9.8
  • TI-2023-16538 Orthanc before 1.12.0 allows authenticated users with access to the Orthanc API to… CVSS 3.1HIGH 8.8
  • TI-2026-04768 Out-of-Bounds Read in DicomImageDecoder (DecodeLookupTable) CVSS 3.1CRITICAL 9.1
  • TI-2026-04763 Memory Exhaustion via Unbounded Content-Length CVSS 3.1HIGH 7.5
See all 11 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences