CVE-2026-5438
Gzip Decompression Bomb via Content-Encoding Header
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Gzip Decompression Bomb via Content-Encoding Header
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.
- Record
CVE-2026-5438- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
EUVDEUVD-2026-20914
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.
- Record
EUVD-2026-20914- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-7vj5-pm38-6wjv
A gzip decompression bomb vulnerability exists when Orthanc processes HTTP request with `Content...
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.
- Record
GHSA-7vj5-pm38-6wjv- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-5438- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-5438
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.
- Record
DEBIAN-CVE-2026-5438- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-5438
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.
- Record
UBUNTU-CVE-2026-5438- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
orthancDebian:12 |
All versions, plus listed versions 1.10.1+dfsg-21.10.1+dfsg-2+deb12u11.12.1+dfsg-11.12.1+dfsg-21.12.1+dfsg-3 Show 31 moreShow less1.12.1+dfsg-41.12.10+dfsg-11.12.10+dfsg-21.12.10+dfsg-31.12.10+dfsg-41.12.10+dfsg-51.12.11+dfsg-11.12.11+dfsg-21.12.11+dfsg-31.12.11+dfsg-41.12.11+dfsg-51.12.11+dfsg-61.12.11+dfsg-71.12.11+dfsg-81.12.2+dfsg-11.12.3+dfsg-11.12.3+dfsg-21.12.4+dfsg-11.12.4+dfsg-21.12.4+dfsg-31.12.4+dfsg-41.12.5+dfsg-11.12.5+dfsg-21.12.6+dfsg-11.12.7+dfsg-11.12.7+dfsg-21.12.7+dfsg-31.12.7+dfsg-41.12.9+dfsg-11.12.9+dfsg-21.13.0+dfsg-1 |
None known |
orthancDebian:13 |
All versions, plus listed versions 1.12.10+dfsg-11.12.10+dfsg-21.12.10+dfsg-31.12.10+dfsg-41.12.10+dfsg-5 Show 12 moreShow less1.12.11+dfsg-11.12.11+dfsg-21.12.11+dfsg-31.12.11+dfsg-41.12.11+dfsg-51.12.11+dfsg-61.12.11+dfsg-71.12.11+dfsg-81.12.7+dfsg-41.12.9+dfsg-11.12.9+dfsg-21.13.0+dfsg-1 |
None known |
orthancDebian:14 |
before 1.12.10+dfsg-4, plus listed versions 1.12.10+dfsg-11.12.10+dfsg-21.12.10+dfsg-31.12.7+dfsg-41.12.9+dfsg-11.12.9+dfsg-2 |
1.12.10+dfsg-4 |
orthancUbuntu:16.04:LTS |
All versions, plus listed versions 0.9.4+dfsg-10.9.4+dfsg-20.9.5+dfsg-11.0.0+dfsg-11.0.0+dfsg-1build1 |
None known |
orthancUbuntu:18.04:LTS |
All versions, plus listed versions 1.3.0+dfsg-1build11.3.0+dfsg-1build21.3.1+dfsg-11.3.1+dfsg-1build11.3.1+dfsg-1build2 |
None known |
orthancUbuntu:20.04:LTS |
All versions, plus listed versions 1.5.7+dfsg-21.5.8+dfsg-21.5.8+dfsg-2ubuntu21.5.8+dfsg-2ubuntu31.5.8+dfsg-2ubuntu41.5.8+dfsg-2ubuntu51.5.8+dfsg-2ubuntu6 |
None known |
orthancUbuntu:22.04:LTS |
All versions, plus listed versions 1.9.2+really1.9.1+dfsg-11.9.7+dfsg-3ubuntu11.9.7+dfsg-3ubuntu21.9.7+dfsg-41.9.7+dfsg-51.9.7+dfsg-61.10.0+dfsg-1 |
None known |
orthancUbuntu:24.04:LTS |
All versions, plus listed versions 1.12.1+dfsg-31.12.1+dfsg-41.12.1+dfsg-4build11.12.2+dfsg-11.12.2+dfsg-1build31.12.2+dfsg-1build4 |
None known |
orthancUbuntu:25.10 |
All versions, plus listed versions 1.12.6+dfsg-11.12.7+dfsg-41.12.7+dfsg-4build2 |
None known |
orthancUbuntu:26.10 |
All versions, plus listed versions 1.12.10+dfsg-21.12.11+dfsg-81.12.11+dfsg-8build1 |
None known |
orthancUbuntu:26.04:LTS |
All versions, plus listed versions 1.12.7+dfsg-4build21.12.9+dfsg-21.12.10+dfsg-11.12.10+dfsg-1build11.12.10+dfsg-2 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-5438 is a high vulnerability (CVSS 7.5) in Orthanc-server Orthanc, published April 9, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.49%, the 42nd percentile. Fixed in orthanc 1.12.10+dfsg-4.