CVE-2026-74562
Received
Received - Intake
Use-After-Free in Linux Kernel IPv6 Routing
Vulnerability report for CVE-2026-74562, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-08-15
Last updated on: 2026-08-15
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
nexthop: take nh->lock for f6i_list walks in replace check and notify
fib6_check_nh_list() and __nexthop_replace_notify() walk nh->f6i_list
during an RTNL-serialized nexthop replace without holding nh->lock. IPv6
RTM_NEWROUTE/RTM_DELROUTE run without RTNL and mutate that list under
nh->lock (fib6_add_rt2node_nh(), fib6_purge_rt()), so both walks race a
concurrent route delete that unlinks and frees a fib6_info:
BUG: KASAN: slab-use-after-free in rt6_fill_node.isra.0 (net/ipv6/route.c:5799)
Read of size 4 at addr ffff888014607e64 by task exploit/143
rt6_fill_node.isra.0 (net/ipv6/route.c:5799)
fib6_rt_update (net/ipv6/route.c:6412)
__nexthop_replace_notify (net/ipv4/nexthop.c:2542)
rtm_new_nexthop (net/ipv4/nexthop.c:2554)
rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)
BUG: KASAN: slab-use-after-free in fib6_check_nh_list (net/ipv4/nexthop.c:1605)
Read of size 8 at addr ffff888014a7d068 by task exploit/142
fib6_check_nh_list (net/ipv4/nexthop.c:1605)
rtm_new_nexthop (net/ipv4/nexthop.c:2575)
rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)
Both walks only read the entries and take no tb6_lock, so protect them
with nh->lock; fib6_rt_update() uses gfp_any(), which returns GFP_ATOMIC
under the lock.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
