Skip to main content
VulnerabilityPublished Updated

CVE-2026-64563: Linux kernel · rhashtable: clear stale iter->p on table restart

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in c39643ad99fea749be50615550e8f0e6d6e60694 : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in c39643ad99fea749be50615550e8f0e6d6e60694, ba510b5e9fe396497d31162acb579f210adfe6c8, a0406c40c6638c5ae50257db6297b2fba6c9ba16 +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 4 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8, < c39643ad99fea749be50615550e8f0e6d6e60694
Fixed in
  • c39643ad99fea749be50615550e8f0e6d6e60694
LinuxLinuxAffected
  • ≥ 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8, < ba510b5e9fe396497d31162acb579f210adfe6c8
Fixed in
  • ba510b5e9fe396497d31162acb579f210adfe6c8
LinuxLinuxAffected
  • ≥ 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8, < a0406c40c6638c5ae50257db6297b2fba6c9ba16
Fixed in
  • a0406c40c6638c5ae50257db6297b2fba6c9ba16
LinuxLinuxAffected
  • ≥ 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8, < 8173f7e2ce67e6ca1d4763f3da14e5b01ce77456
Fixed in
  • 8173f7e2ce67e6ca1d4763f3da14e5b01ce77456
LinuxLinuxAffected
  • ≥ 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8, < 4169d9fb92f313ff8e7e83d733c1ecdcc93eebd3
Fixed in
  • 4169d9fb92f313ff8e7e83d733c1ecdcc93eebd3
LinuxLinuxAffected
  • ≥ 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8, < 0955b65c2b47c30b439e2cf1b1e375073aa0413a
Fixed in
  • 0955b65c2b47c30b439e2cf1b1e375073aa0413a

Description

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

References

Community reviews

Loading reviews…