High severity · published Apr 6, 2026
CVE-2026-31407
netfilter: conntrack: add missing netlink policy validations
7.1
CVSS
0.2%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved:
netfilter: conntrack: add missing netlink policy validations
Hyunwoo Kim reports out-of-bounds access in sctp and ctnetlink.
These attributes are used by the kernel without any validation.
Extend the netlink policies accordingly.
Quoting the reporter:
nlattr_to_sctp() assigns the user-supplied CTA_PROTOINFO_SCTP_STATE
value directly to ct->proto.sctp.state without checking that it is
within the valid range. [..]
and: ... with exp->dir = 100, the access at
ct->master->tuplehash[100] reads 5600 bytes past the start of a
320-byte nf_conn object, causing a slab-out-of-bounds read confirmed by
UBSAN.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
2.6.27 before 6.6.136; 6.7 before 6.12.83; 6.13 before 6.18.24; 6.19 before 6.19.10; 7.0; 7.0; +2 more · source: NVD
LI
Linux · Linux
a258860e01b80e8f554a4ab1a6c95e6042eb8b73 before e7b5766693477c52424cc6c79dd30a7a9c7db52c; a258860e01b80e8f554a4ab1a6c95e6042eb8b73 before 78bba9f73942aa7dca47d817d8cec0fb9b443b70; a258860e01b80e8f554a4ab1a6c95e6042eb8b73 before be88a337bf07afb1ee173f1099294d1b7ab3fefe; a258860e01b80e8f554a4ab1a6c95e6042eb8b73 before c5e918390002edf0cff80a0e7ce1f86f16a9507c; a258860e01b80e8f554a4ab1a6c95e6042eb8b73 before 9174d28f3f15d8c4962f5980c0be167633880443; a258860e01b80e8f554a4ab1a6c95e6042eb8b73 before 67c53c1978cef3c504237275e39c857e2f6af56e; +3 more · source: vendor
SS
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem · Siemens
0 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-31407
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-31407
Patch
https://git.kernel.org/stable/c/0fbae1e74493d5a160a70c51aeba035d8266ea7d
Patch
https://git.kernel.org/stable/c/67c53c1978cef3c504237275e39c857e2f6af56e
git.kernel.org
https://git.kernel.org/stable/c/78bba9f73942aa7dca47d817d8cec0fb9b443b70
Patch
https://git.kernel.org/stable/c/9174d28f3f15d8c4962f5980c0be167633880443
git.kernel.org
https://git.kernel.org/stable/c/be88a337bf07afb1ee173f1099294d1b7ab3fefe
Patch
https://git.kernel.org/stable/c/c5e918390002edf0cff80a0e7ce1f86f16a9507c
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