What’s Vulnerable › Vulnerabilities

CVE-2026-93204: batman-adv: dat: atomically update mac addresses

• Severity: unknown
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-17 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: batman-adv: dat: atomically update mac addresses When a MAC address is updated in batadv_dat_entry_add(), it is done using a simple copy function. A parallel reader might only see parts of this update. In worst case, the reader is transporting the half updated MAC address over the network or is creating an ARP response using it - poisoning the ARP cache. atomic64_t can be used to store the 48 bit of a mac address. A reader will then either see the old mac address or the new one - never a mixture of both.

Affected products

• Linux kernel: 3.8 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.3. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/159360a0de831845c4500b4f8638decdcd624040
• https://git.kernel.org/stable/c/1674855a5b6eacfe35f4db3095d7055c25467274
• https://git.kernel.org/stable/c/181012b3d29c51197c235ee5871fc7512c736855
• https://git.kernel.org/stable/c/259db2c04586d40b82c5c3002b1e28b0698a0bb7
• https://git.kernel.org/stable/c/66238e2a74eca5dabf85b0cd2c3c944e474dc2fd
• https://git.kernel.org/stable/c/a5e4d6cb4f6848b8906c1c493f99a8ccc0638515
• https://git.kernel.org/stable/c/e6de568d3eda3e3c01c868fabd7a9535d5ee4a73
• https://git.kernel.org/stable/c/f68038c77a2f38c09c7e2e4f7fa1f4e246fdf2c9

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