CVE-2026-64563

High

In the Linux kernel, the following vulnerability has been resolved: rhashtable: clear stale iter->p on table restart rhashtable_walk_start_check() has two restart paths when resuming a walk. When iter->walker.tbl is valid, it re-validates iter->p against the table and sets iter->p = NULL if the object is gone. When iter->walker.tbl is NULL (table was freed during resize), it resets slot and skip but forgets to clear iter->p. rhashtable_walk_next() then dereferences the stale iter->p, reading freed memory. This is a use-after-free. Any caller that does multi-fragment rhashtable walks across walk_stop/walk_start boundaries is affected. Concrete cases include netlink_diag (__netlink_diag_dump in net/netlink/diag.c) and TIPC (tipc_nl_sk_walk in net/tipc/socket.c). Crash stack (netlink_diag): BUG: KASAN: slab-use-after-free in rhashtable_walk_next+0x365/0x3c0 Read of size 8 at addr ffff88801a9d2438 (freed kmalloc-2k, offset 1080) Call Trace: rhashtable_walk_next+0x365/0x3c0 (lib/rhashtable.c:1016) __netlink_diag_dump+0x160/0x760 (net/netlink/diag.c:122) netlink_diag_dump+0xc2/0x240 netlink_dump+0x5bc/0x1270 netlink_recvmsg+0x7a3/0x980 sock_recvmsg+0x1bc/0x200 __sys_recvfrom+0x1d4/0x2c0

Package Linux Kernel
Published 2026-08-04
Last modified 2026-08-19
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.8

out of 10
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected versions

Linux kernel versions 4.18 and later are affected. Fixed in 5.10.265, 5.15.216, 6.1.183, 6.6.151, 6.12.103, 6.18.42, 7.1.6, 7.2 and their respective stable series.

Affected from
≥ 4.18
Fixed in
✓ 5.10.265 5.10.x ✓ 5.15.216 5.15.x ✓ 6.1.183 6.1.x ✓ 6.6.151 6.6.x ✓ 6.12.103 6.12.x ✓ 6.18.42 6.18.x ✓ 7.1.6 7.1.x ✓ 7.2

References

8 total
Showing 5 of 8 references View all on NVD

Frequently asked questions

  • What is CVE-2026-64563?

    CVE-2026-64563 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 4.18 onward and has been patched in 5.10.265, 5.15.216, 6.1.183 and others. CVE-2026-64563 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-64563?

    CVE-2026-64563 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2026-64563?

    Yes. CVE-2026-64563 has been patched. Fixed versions include 5.10.265, 5.15.216, 6.1.183 and others. If you are running Linux kernel 4.18 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-64563 actively exploited?

    No. CVE-2026-64563 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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