CVE-2026-99072 is a vulnerability in Linux Kernel
Published on October 23, 2026
ipv4: stop route notification sizing when nexthop group shrinks
In the Linux kernel, the following vulnerability has been resolved:
ipv4: stop route notification sizing when nexthop group shrinks
Commit 680aea08e78c ("net: ipv4: Emit notification when fib
hardware flags are changed") added an RCU-only fib_nlmsg_size() call
for asynchronous hardware flag notifications.
fib_nlmsg_size() checks fib_info_num_path() before each iteration,
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 fib_nexthop_nlmsg_size() dereferences
it.
Stop sizing when the indexed path is absent. Nexthop groups are
dense, so the current snapshot has no later path.
Products Associated with CVE-2026-99072
Want to know whenever a new CVE is published for Linux Kernel? stack.watch will email you.
Affected Versions
Linux:- Version 680aea08e78c003292415518ad270bc20f9c80b1 and below 72d9d17092bb37b0717f12042a0817d01a1f9e78 is affected.
- Version 680aea08e78c003292415518ad270bc20f9c80b1 and below ad1c9f1b98c92609e9bb2ae8f05916defc3b0a54 is affected.
- Version 680aea08e78c003292415518ad270bc20f9c80b1 and below c1f48d1c2d5e9efd904dbbc2f2b3d41543e55c49 is affected.
- Version 680aea08e78c003292415518ad270bc20f9c80b1 and below ad2b3a68b8a7d5d27de88e05674e4adb1ce46d88 is affected.
- Version 680aea08e78c003292415518ad270bc20f9c80b1 and below d3daa33c7af92e38f2274bbd2576f58bfbaf89e6 is affected.
- Version 5.12 is affected.
- Before 5.12 is unaffected.
- Version 6.6.160, <= 6.6.* is unaffected.
- Version 6.12.113, <= 6.12.* is unaffected.
- Version 6.18.57, <= 6.18.* is unaffected.
- Version 7.2.11, <= 7.2.* is unaffected.
- Version 7.3, <= * is unaffected.