CVE-2026-55222 (GCVE-0-2026-55222)
Vulnerability from cvelistv5 – Published: 2026-10-23 14:31 – Updated: 2026-10-23 20:57
VLAI
EPSS
VEX
Title
Isar: Unprivileged user ownership of trusted repository GPG public keys storage after bootstrap
Summary
Isar is an integration system for automated root filesystem generation. In versions 0.11 and newer, /etc/apt/trusted.gpg.d is created manually during bootstrap setup to be able to deploy local keys. By that, the directory is owned by the calling user (the one that executes Isar) instead of root. If the calling user's id is identical to one of an unprivileged user inside the image, this user is able to alter existing keys and deploy new ones, silently breaking the apt repo integrity protection. The issue is has no impact on those images that use an immutable rootfs, or if apt is never invoked. Changing only the keys does not trigger an exploit, it's just one step in a chain. An attacker would also have to manipulate a remote repo or intercept non-secure communication with it. This issue has been patched via commit 29e84ed.
Severity
5.1 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-23 20:43 UTC
CWE
- CWE-1290 - Incorrect Decoding of Security Identifiers
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/ilbers/isar/security/advisorie… | x_refsource_CONFIRM |
| https://github.com/ilbers/isar/commit/29e84ed301c… | x_refsource_MISC |
Impacted products
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Sightings
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|---|
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.