VULNERABILITY INTELLIGENCE

CVE-2026-55222

CVSS score5.1 MEDIUM
EPSS probability0.13%
CISA KEVNot currently listed
Published2026-10-23
Last modified2026-10-23
CVSS vectorCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Description

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.

Weakness classification

  • security-advisories@github.com: CWE-1290

Primary references