CVE-2022-4128 — A NULL pointer dereference issue was discovered in the Linux kernel in the MPTCP

A NULL pointer dereference issue was discovered in the Linux kernel in the MPTCP protocol when traversing the subflow list at disconnect time. A local user could use this flaw to potentially crash the system causing a denial of service.

01What is this vulnerability?

A NULL pointer dereference issue was discovered in the Linux kernel in the MPTCP protocol when traversing the subflow list at disconnect time. A local user could use this flaw to potentially crash the system causing a denial of service.

02Affected products

Vendor	Product	Versions
n	a / Linux kernel (mptcp)	Fixed in 5.19

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2022-11-28T00:00:00.000Z
• Last modified: 2025-04-14T18:08:50.265Z

09References

• lore.kernel.org — https://lore.kernel.org/netdev/20220708233610.410786-2-mathew.j.martineau%40linu…
• github.com — https://github.com/torvalds/linux/commit/5c835bb142d4