CVE-2026-54548

kas: Persistent SSH Host Key Checking Disablement

LOW
3.3
CVSS Score
Published: August 26, 2026 at 02:17 PM UTC
Updated: September 9, 2026 at 09:27 PM UTC
1 product affected across 1 vendorKas

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Severity
LOW3.3
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

Description

kas is a setup tool for bitbake based projects. Prior to 5.4, internal SSH key setup triggered by SSH_PRIVATE_KEY or SSH_PRIVATE_KEY_FILE creates ~/.ssh/config when no user-specific SSH configuration exists and adds a global Host * rule containing StrictHostKeyChecking no. In kas/libcmds.py, ssh_no_host_key_check() runs without checking ctx.managed_env, so the setting persists after kas exits and affects future SSH sessions by the same local user, extending beyond the intended short-lived continuous integration environment. A later SSH connection can therefore accept an attacker-controlled host key without verification, increasing the risk of a man-in-the-middle attack that compromises session confidentiality or integrity. This issue is fixed in version 5.4.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 5.4
Affected range stops below 5.4, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

3.3LOWGitHub_M
Attack Vector
LOCAL
Complexity
HIGH
Privileges
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-295

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