CVE-2026-55222 (GCVE-0-2026-55222)

Vulnerability from cvelistv5 – Published: 2026-10-23 14:31 – Updated: 2026-10-23 20:57
VLAI
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)
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
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
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7761 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
ilbers isar Affected: >= 0.11, <= 1.1
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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