Isar: Unprivileged user ownership of trusted repository GPG public keys storage after bootstrap
CVSS score
5.1
EPSS probability
—
Risk score
0.5
Published
3 h ago
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Impact on My Inventory
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Vulnerability description
DayBreach AI Explanation
Verified against sourcesSources read
1
Source agreement
Tam uyum
Evidence confidence
%55
Short explanation
CVE-2026-55222 is a medium severity integrity vulnerability affecting the Isar automated root filesystem generation system. During bootstrap setup, the /etc/apt/trusted.gpg.d directory is owned by the calling user instead of root, allowing unprivileged users to alter GPG keys [S0].
This vulnerability silently breaks apt repository integrity protection, potentially enabling attackers to manipulate package verification mechanisms within the image [S0].
What should be done?
- Monitor vendor advisories and related commit references [S0].
- Follow vendor guidance when exact fixed versions are absent [S0].
Chain of evidence and sources
Isar sürümlerinde /etc/apt/trusted.gpg.d dizini root yerine çağıran kullanıcıya ait olabilmektedir [S0].
Bu zafiyet apt depo bütünlük korumasını sessizce bozabilmektedir [S0].
Show the technical text from the sources
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.
CVSS vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
CWE: CWE-1290
This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.
IMPACT: Affected Products and Software
Affected Products
The following products are affected by CVE-2026-55222 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.
| ID | VENDOR | PRODUCT | ACTION |
|---|---|---|---|
| 1 | ilbers | isar | View |
RED HAT CSAF/VEX: Product Impact Check
SCORING: CVSS from Multiple Sources
CVSS Scores
The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.
| SCORE | VERSION | SEVERITY | VECTOR | SOURCE |
|---|---|---|---|---|
| 5.1 | CVSS V3_1 | MEDIUM | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N | CVE CNA |
| 5.1 | CVSS V31 | MEDIUM | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N | NVD |
Patch and Remediation Guide
Solution & Remediation Advisory
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Public exploit and active exploitation status
Verified exploit intelligence
No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.
Weakness Classification and Attack Patterns (CWE & CAPEC)
CWE - Common Weakness Enumeration
While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-55222 is associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-55222 weaknesses.
Attack Vector and Accessibility
Official Sources and Advisories
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