CVE-2026-41861: Arbitrary Root File Write via Path Traversal in BOSH agent
Path Traversal in BOSH-Ecosystem / BOSH allows an IaaS-metadata attacker to make the agent write a root-owned file with partially attacker-controlled body to any path ending in .network, and create any missing parent directories with mode 0777 via network Alias on Ubuntu.
Affected versions: BOSH agent < v2.847.0 (jammy <= v1.1202, or noble <= v1.364). Lower bound unspecified in advisory ("All bosh agent versions").
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
bosh agentto a version that resolves this vulnerability.Fixed in v2.847.0 - Configuration
Do not allow BOSH agent to create missing parent directories with mode 0777 via network Alias on Ubuntu; ensure created parent directories do not use 0777 permissions.
Ubuntu (network Alias / BOSH network Alias behavior) parent directory permissions = mode 0777
Event History
Frequently Asked Questions
What is the severity of CVE-2026-41861?
The severity of CVE-2026-41861 is rated as medium with a score of 4.2.
What does CVE-2026-41861 affect?
CVE-2026-41861 affects the BOSH agent within the BOSH ecosystem.
How can CVE-2026-41861 be exploited?
CVE-2026-41861 can be exploited via a path traversal vulnerability allowing attackers to write root-owned files.
What versions of BOSH are affected by CVE-2026-41861?
CVE-2026-41861 affects BOSH agent versions that are susceptible to path traversal exploits.
How do I fix CVE-2026-41861?
To fix CVE-2026-41861, you should update to the latest version of the BOSH agent that addresses this vulnerability.