CVE-2026-97472

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

ipv6: addrconf: fix temp address generation after prefix deprecation

When a router temporarily deprecates an IPv6 prefix (either by sending a

Router Advertisement with Preferred Lifetime = 0 or by letting the

lifetime expire) and later restores it, the kernel permanently loses its

ability to generate temporary privacy addresses (RFC 8981) for that

prefix.

This happens because the address worker attempts to generate a

replacement temporary address when the current one nears expiration. As

the base prefix is deprecated already, the generation fails after

marking the temporary address as already having spawned a replacement

(ifp->regen_count++).

When the router eventually restores the prefix, the temporary address

becomes active again. However, once it naturally expires, the address

worker sees this temporary address already tried to generate one and

skips the regeneration.

Fix the issue by resetting the regen_count

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References