In plain language
What this advisory means
A flaw was found in how the Linux kernel handles wireless network packets in certain mesh networks. This flaw could let someone nearby inject fake data packets into the network. Additionally, multiple other security issues in different Linux kernel components could let attackers compromise a system. Updating the Linux kernel fixes these problems.
Technical explanation
How the issue affects the environment
Researchers Siebe Devroe, Héloïse Gollier, and Mathy Vanhoef identified an issue in the Linux kernel's WiFi implementation. It failed to correctly handle aggregated frames in mesh networks due to an incorrect fix for CVE-2020-24588. A physically proximate attacker could exploit this to inject malicious packets (CVE-2025-27558). Beyond this, numerous security vulnerabilities were found in various kernel subsystems, including x86 architecture, InfiniBand and network drivers, NVME storage drivers, Ext4 and SMB file systems, IPv4 and IPv6 networking stacks, network traffic control, TCP protocol handling, locking mechanisms, Multipath TCP, Netfilter, SCTP protocol, and SMC sockets. These vulnerabilities could potentially allow attackers to compromise the affected systems.
Operational impact
Why teams should care
These vulnerabilities pose risks of unauthorized network access and system compromise, which could lead to data breaches, service disruption, or unauthorized control over affected systems running Ubuntu on Azure cloud virtual machines. Organizations using these systems should update promptly to reduce exposure and maintain security compliance.
Immediate action
Update the Linux kernel packages to the specified patched versions, then reboot the system to apply all changes. Note that due to an application binary interface (ABI) change, third-party kernel modules must be recompiled and reinstalled after the kernel update.
Affected and fixed releases
Temporary risk reduction
No separate workaround was supplied in the source feed. Use the official vendor advisory before changing production controls.
Evidence and validation checklist
- Discovery of WiFi aggregated frames vulnerability in mesh networks (CVE-2025-27558) by Siebe Devroe, Héloïse Gollier, and Mathy Vanhoef
- Multiple security issues identified in Linux kernel subsystems including networking, file systems, and drivers
- Updates provided that correct these flaws requiring system reboot and recompilation of third-party kernel modules
- Advisory published by Ubuntu Security Notices on August 17, 2026
Authoritative reference
Ubuntu Security Notices
QCS detected and normalized this record from the official source. Vendor guidance remains authoritative.