High severity · published Mar 25, 2026
CVE-2026-23392
netfilter: nf_tables: release flowtable after rcu grace period on error
7.8
CVSS
0.2%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: release flowtable after rcu grace period on error
Call synchronize_rcu() after unregistering the hooks from error path,
since a hook that already refers to this flowtable can be already
registered, exposing this flowtable to packet path and nfnetlink_hook
control plane.
This error path is rare, it should only happen by reaching the maximum
number hooks or by failing to set up to hardware offload, just call
synchronize_rcu().
There is a check for already used device hooks by different flowtable
that could result in EEXIST at this late stage. The hook parser can be
updated to perform this check earlier to this error path really becomes
rarely exercised.
Uncovered by KASAN reported as use-after-free from nfnetlink_hook path
when dumping hooks.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 6% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
4.16.1 before 6.1.167; 6.2 before 6.6.130; 6.7 before 6.12.78; 6.13 before 6.18.20; 6.19 before 6.19.10; 4.16; +7 more · source: NVD
LI
Linux · Linux
3b49e2e94e6ebb8b23d0955d9e898254455734f8 before d2632de96ccb066e0131ad1494241b9c281c60b8; 3b49e2e94e6ebb8b23d0955d9e898254455734f8 before adee3436ccd29f1e514c028899e400cbc6d84065; 3b49e2e94e6ebb8b23d0955d9e898254455734f8 before 7e3955b282eae20d61c75e499c75eade51c20060; 3b49e2e94e6ebb8b23d0955d9e898254455734f8 before c8092edb9a11f20f95ccceeb9422b7dd0df337bd; 3b49e2e94e6ebb8b23d0955d9e898254455734f8 before e78a2dcc7cfb87b64a631441ca7681492b347ef6; 3b49e2e94e6ebb8b23d0955d9e898254455734f8 before d73f4b53aaaea4c95f245e491aa5eeb8a21874ce; +1 more · source: vendor
SS
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP · Siemens
V3.1.6; V3.1.5; V3.1.7; V3.1.6; V3.1.5; V3.1.7 · source: CISA
SS
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP · Siemens
V3.1.6; V3.1.5; V3.1.7; V3.1.6; V3.1.5; V3.1.7 · source: CISA
SS
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem · Siemens
0 · source: CISA
SS
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP · Siemens
V3.1.6; V3.1.5; V3.1.7 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-23392
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-23392
Patch
https://git.kernel.org/stable/c/7e3955b282eae20d61c75e499c75eade51c20060
Patch
https://git.kernel.org/stable/c/adee3436ccd29f1e514c028899e400cbc6d84065
Patch
https://git.kernel.org/stable/c/c8092edb9a11f20f95ccceeb9422b7dd0df337bd
Patch
https://git.kernel.org/stable/c/d2632de96ccb066e0131ad1494241b9c281c60b8
Patch
https://git.kernel.org/stable/c/d73f4b53aaaea4c95f245e491aa5eeb8a21874ce
Patch
https://git.kernel.org/stable/c/e78a2dcc7cfb87b64a631441ca7681492b347ef6
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