Buffer overflow in Linux

CVE-2026-31407

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.

Vulnerability class: Buffer Overflow

EPSS: 0.002 (6.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-31407?
CVE-2026-31407 is a high-severity vulnerability in Linux, classified under Out-of-bounds Write. CVSS score: 7.1/10. Published 2026-04-06.
How severe is CVE-2026-31407?
High severity. CVSS v3 base score is 7.1 out of 10.