CVE-2026-55222

Published Oct 23, 2026

Last updated 2 days ago

Overview

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.
Source
security-advisories@github.com
NVD status
Deferred

Risk scores

CVSS 3.1

Type
Secondary
Base score
5.1
Impact score
3.6
Exploitability score
1.4
Vector string
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Severity
MEDIUM

Weaknesses

security-advisories@github.com
CWE-1290

Social media

Hype score
Not currently trending