OCTOBER 9, 2026
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Case File

CVE-2026-97940

HIGH · CVSS 7.8 EPSS 0.16%

Source: NVD + CISA KEV + EPSS · Published 2026-09-25 · Last synced 2026-10-09

CyberRota Analysis

AI-Generated

The vulnerability affects the Linux kernel's IPv6 routing functionality, specifically in the handling of fib6 walkers, which can lead to a use-after-free condition. This flaw allows a freed walker to be accessed during subsequent route deletions, potentially resulting in system instability or exploitation. Organizations using Linux systems with IPv6 routing enabled should prioritize addressing this vulnerability to mitigate risks associated with potential exploitation.

CVE
CVE-2026-97940
Severity
HIGH
CVSS
7.8
EPSS
0.16%
Linux

Original NVD Description

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.