SB20260528180 - Improper input validation in Linux kernel net xen-netback driver
Published: May 28, 2026
Security Bulletin ID
SB20260528180
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Adjecent network
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper input validation (CVE-ID: CVE-2026-45890)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to improper input validation in the xen-netback backend connect() function when processing the guest-controlled xenbus key "multi-queue-num-queues". A remote user can write a zero queue count to trigger a host panic to cause a denial of service.
Impact on the host occurs on systems configured with panic_on_warn=1.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/2993e0f904c45f8af12917344bb1cac7ccd05a60
- https://git.kernel.org/stable/c/654780dee9eae419e1648ea58462c4efe54518fa
- https://git.kernel.org/stable/c/6d1dc8014334c7fb25719999bca84d811e60a559
- https://git.kernel.org/stable/c/787bfa423228c4b02ba3368128f625d579085353
- https://git.kernel.org/stable/c/88b0fced1bbbfdb356a007592604008ffc93a6a1
- https://git.kernel.org/stable/c/ce66d6786de45b7ed9cbbdc0988054bf09e58f54
- https://git.kernel.org/stable/c/d99f69ddc70fd9f4b8148add62209a1a8eb5c615
- https://git.kernel.org/stable/c/ec4859ac5c933e3315543a61adc1ca4358006a41