libnbd vulnerability

A flaw was found in libnbd. A malicious actor could exploit this by convincing libnbd to open a specially crafted Uniform Resource Identifier (URI). This vulnerability arises because non-standard hostnames starting with '-o' are incorrectly interpreted as arguments to the Secure Shell (SSH) process, rather than as hostnames. This could lead to arbitrary code execution with the privileges of the user running libnbd.

Published 19 Dec 2025Updated 7 Oct 20263 sources
CVSS 4.8

What happened

A flaw was found in libnbd. A malicious actor could exploit this by convincing libnbd to open a specially crafted Uniform Resource Identifier (URI). This vulnerability arises because non-standard hostnames starting with '-o' are incorrectly interpreted as arguments to the Secure Shell (SSH) process, rather than as hostnames. This could lead to arbitrary code execution with the privileges of the user running libnbd.

Affected versions

libnbd: 1.22.0 through before 1.22.5 (semver); 1.23.0 through before 1.23.9 (semver) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.