Linux Kernel up to 6.19.9/7.0-rc4 netfilter nlattr_to_sctp out-of-bounds

Summaryinfo

A vulnerability marked as critical has been reported in Linux Kernel up to 6.19.9/7.0-rc4. Affected by this issue is the function nlattr_to_sctp of the component netfilter. The manipulation leads to out-of-bounds. This vulnerability is traded as CVE-2026-31407. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.19.9/7.0-rc4. It has been rated as problematic. This issue affects the function nlattr_to_sctp of the component netfilter. The manipulation with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality. The summary by CVE is:

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.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-31407 since 03/09/2026. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/06/2026).

Upgrading to version 6.19.10 or 7.0-rc5 eliminates this vulnerability. Applying the patch 0fbae1e74493d5a160a70c51aeba035d8266ea7d/f900e1d77ee0ef87bfb5ab3fe60f0b3d8ad5ba05 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-19197). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3
• 6.19.4
• 6.19.5
• 6.19.6
• 6.19.7
• 6.19.8
• 6.19.9
• 7.0-rc1
• 7.0-rc2
• 7.0-rc3
• 7.0-rc4

License

• open-source

Website

• Vendor: https://www.kernel.org/

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