CVE-2026-33542: CWE-295: Improper Certificate Validation in lxc incus
Incus is a system container and virtual machine manager. Prior to version 6.23.0, a lack of validation of the image fingerprint when downloading from simplestreams image servers opens the door to image cache poisoning and under very narrow circumstances exposes other tenants to running attacker controlled images rather than the expected one. Version 6.23.0 patches the issue.
AI Analysis
Technical Summary
Incus, a system container and virtual machine manager, had a vulnerability (CVE-2026-33542) due to improper certificate validation (CWE-295). Before version 6.23.0, incus did not validate the image fingerprint when downloading images from simplestreams image servers. This allowed potential image cache poisoning and could expose other tenants to malicious images under very limited circumstances. The vulnerability has a CVSS 4.0 score of 5.7 (medium severity) and was patched in version 6.23.0.
Potential Impact
Successful exploitation can result in image cache poisoning, which may cause other tenants to run attacker-controlled images instead of legitimate ones. This could lead to unauthorized code execution within container or virtual machine environments. However, the conditions for cross-tenant impact are very narrow, limiting the scope of the threat.
Mitigation Recommendations
Upgrade incus to version 6.23.0 or later, where the issue is patched. Since this is not a cloud service, remediation requires applying the official fix provided by the vendor. Patch status is confirmed by the vendor advisory indicating version 6.23.0 addresses the vulnerability.
CVE-2026-33542: CWE-295: Improper Certificate Validation in lxc incus
Description
Incus is a system container and virtual machine manager. Prior to version 6.23.0, a lack of validation of the image fingerprint when downloading from simplestreams image servers opens the door to image cache poisoning and under very narrow circumstances exposes other tenants to running attacker controlled images rather than the expected one. Version 6.23.0 patches the issue.
CVSS v4.0
Score 5.7medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Incus, a system container and virtual machine manager, had a vulnerability (CVE-2026-33542) due to improper certificate validation (CWE-295). Before version 6.23.0, incus did not validate the image fingerprint when downloading images from simplestreams image servers. This allowed potential image cache poisoning and could expose other tenants to malicious images under very limited circumstances. The vulnerability has a CVSS 4.0 score of 5.7 (medium severity) and was patched in version 6.23.0.
Potential Impact
Successful exploitation can result in image cache poisoning, which may cause other tenants to run attacker-controlled images instead of legitimate ones. This could lead to unauthorized code execution within container or virtual machine environments. However, the conditions for cross-tenant impact are very narrow, limiting the scope of the threat.
Mitigation Recommendations
Upgrade incus to version 6.23.0 or later, where the issue is patched. Since this is not a cloud service, remediation requires applying the official fix provided by the vendor. Patch status is confirmed by the vendor advisory indicating version 6.23.0 addresses the vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-03-20T18:05:11.832Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 69c5ba613c064ed76fe1f5cb
Added to database: 03/26/2026, 22:59:45 UTC
Last enriched: 04/03/2026, 13:10:56 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 133
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