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CVE-2026-64190 Linux CVE debrief

A race condition vulnerability was found in the Linux kernel's team device driver. The bug occurs when a mode change is concurrent with transmit on the team device, leading to a NULL pointer dereference and a potential kernel crash. The vulnerability requires CAP_NET_ADMIN privileges to exploit. This issue arises from a race between team_xmit() and __team_change_mode(), where the latter clears team->ops, potentially causing team_xmit() to call a NULL function pointer. The fix replaces memset()/memcpy() with per-field updates that avoid touching transmit or receive handlers, managed solely by team_adjust_ops(). Affected systems include those using the Linux kernel with team device drivers. Defenders should focus on applying patches and restricting access to team device configuration. Evidence suggests that the fix prevents NULL pointer dereferences during mode changes, but defenders must proceed with caution and monitor for similar vulnerabilities due to limited details on all affected systems.

Vendor
Linux
Product
Unknown
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-20
Original CVE updated
2026-08-11
Advisory published
2026-07-20
Advisory updated
2026-08-11

Who should care

Linux kernel developers and maintainers, users of Linux distributions, administrators of systems using the Linux kernel, and security teams responsible for vulnerability management and patching. These stakeholders should be aware of the vulnerability and take steps to mitigate it, especially if they use team devices in their Linux kernel deployments.

Technical summary

The Linux kernel's team device driver is vulnerable to a race condition that can lead to a NULL pointer dereference during mode changes. This occurs when team_xmit() runs concurrently with __team_change_mode(), which clears team->ops. The fix involves updating team->ops in a way that avoids NULL pointer dereferences. Affected systems include those using the Linux kernel with team device drivers. Defenders should focus on applying patches and restricting access to team device configuration.

Defensive priority

Medium priority due to the specific conditions required for exploitation and the availability of patches.

Recommended defensive actions

  • Apply the available patches from the Linux kernel stable tree.
  • Restrict access to team device configuration to trusted users.
  • Monitor for similar vulnerabilities in the Linux kernel.
  • Review compensating controls for exposed systems while remediation is scheduled and verified.
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review.
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented.
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The vulnerability was resolved in the Linux kernel by replacing memset()/memcpy() with per-field updates that never touch transmit or receive handlers, which are managed solely by team_adjust_ops(). To verify, defenders should review the Linux kernel stable tree for patches and assess their team's exposure. Evidence limits suggest that the fix prevents NULL pointer dereferences during mode changes. However, without specific details on all affected systems, defenders must proceed with caution and monitor for similar vulnerabilities.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-20T17:18:22.117Z and has not been modified since then.