CVE-2026-97472

What the bug is

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 check of the latest temp address generated for the prefix updated by the incoming RA.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

net/ipv6/addrconf.c

What this is

NETWORKING [IPv4/IPv6]MAINTAINERS section matched on net/ipv6/addr* · netdev@vger.kernel.org · Maintained

Check it on the machine

grep -w CONFIG_IPV6 /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

Show whether Debian builds this, per release

Debian builds this code. Every release below compiles the affected file into the kernels it ships.

• bookworm, trixie, forky, sid, bookworm · linux-6.12y

y

built into the kernel image on every flavour - only a patch removes it

Build switch

CONFIG_IPV6

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-09-24 (24 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.17%, higher than 6.2% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

net/ipv6

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
3.2	5.10.271	b00f7c1da82a
3.2	5.15.222	6da8ba900b85
3.2	6.1.189	4f7d2a8dc364
3.2	6.6.158	f601ec5c92b3
3.2	6.12.111	bff7b87dfa28
3.2	6.18.53	4df5597c6544
3.2	7.2	e20d8922aa8f

Debian advisories