CVE-2026-99073
Published Oct 23, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: ipv4: stop exception dump when nexthop group shrinks Commit 4ce5dc9316de ("inet: switch inet_dump_fib() to RCU protection") allowed IPv4 FIB dumps to run concurrently with nexthop replacement. fib_dump_info_fnhe() uses fib_info_num_path() as the loop bound, then fib_info_nhc() independently reloads nh->nh_grp. If RTM_NEWNEXTHOP replaces a group with fewer paths between those loads, fib_info_nhc() returns NULL and the dump dereferences it through nhc_flags. Stop the walk when the indexed path is absent. Nexthop groups are dense, so the current snapshot has no later path.
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References
Other References
Frequently Asked Questions
What is CVE-2026-99073? +
In the Linux kernel, the following vulnerability has been resolved:
ipv4: stop exception dump when nexthop group shrinks
Commit 4ce5dc9316de ("inet: switch inet_dump_fib() to RCU
protection") allowed IPv4 FIB dumps to run concurrently with nexthop
replacement.
fib_dump_info_fnhe() uses fib_info_num_path() as the loop bound,
then fib_info_nhc() independently reloads nh->nh_grp. If
RTM_NEWNEXTHOP replaces a group with fewer paths between those loads,
fib_info_nhc() returns NULL and the dump dereferences it through
nhc_flags.
Stop the walk when the indexed path is absent. Nexthop groups are
dense, so the current snapshot has no later path.
How do I check if I'm vulnerable to CVE-2026-99073? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.