Linux Kernel Netfilter Out-Of-Bounds Write Rated 7.1 CVSS

Last refreshed2026-10-15

Status: UPDATED | Advisory ID: CVE-2026-31407

Key Details

CVE	CVE-2026-31407
CVSS Score / Version	7.1 (High) / CVSS v3.1
Updated	2026-10-15
CVSS Vector	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H`
CVSS Prose	attack vector is local; attack complexity is low; privileges required is low; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is none; availability impact is high.
Affected products	Linux Kernel and Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
Classified as	CWE-787 (Out-of-bounds Write)
Exploitation prediction (EPSS)	0.17% probability of exploitation in the next 30 days (6% percentile) -- FIRST.org's EPSS model.

Vendor	Product	Affected Versions	Patch Status
Linux	Linux Kernel
Siemens	SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

Vendor

Product

Affected Versions

Patch Status

Linux

Linux Kernel

Siemens

SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

Subsystems	Controllers & Field I/O, OT Supporting Infrastructure
Sectors	All Sectors

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. (NVD)

Monitor Linux's and Siemens's web pages for any future patch releases.

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-31407
CVE	https://www.cve.org/CVERecord?id=CVE-2026-31407

Source

Reference

NVD

CVE