Microsoft Security Response Center guidance
Vendor revision: Oct 15, 2026Release Notes
Vendor-listed releases
- 6.6.158.1-1
Vulnerability intelligence
CVE-2026-97940 and is rated High severity with a CVSS score of 7.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
Release Notes
Vendor-listed releases
In the Linux kernel, the following vulnerability has been resolved:
ipv6: fix fib6 walker UAF on seq stop
ipv6_route_iter_active() treats a walker in FWS_U at the table root as already unlinked. fib6_del_route() can move a still-linked walker into that same state when the current leaf is the last route at the root, so ipv6_route_native_seq_stop() skips fib6_walker_unlink(). The seq private object can then be freed while it remains on net->ipv6.fib6_walkers.
A later route deletion walks the dangling list and uses the freed walker.
Use the list head as membership state and reinitialize it when unlinking. Keep the existing w->node check so a never-started iterator with a zeroed private object is not treated as linked.
The same stop helper is used by /proc/net/ipv6_route and by the BPF ipv6_route iterator. The BPF show path only widens the race.
Source: NVD