CVE-2026-31669 - Vulnerability Analysis

Overview

Linux kernel contains a use-after-free vulnerability in MPTCP caused by improper slab cache initialization in mptcp_subflow_init, letting attackers trigger slab-use-after-free in __inet_lookup_established, exploit requires concurrent ehash lookups under RCU read lock.

Severity & Score

Impact

Attackers can cause use-after-free memory access, potentially leading to system crashes or arbitrary code execution.

Mitigation

Update to the latest Linux kernel version containing the fix for mptcp_subflow_v6_init initialization.

References

• https://git.kernel.org/stable/c/15fa9ead4d5e6b6b9c794e84144146c917f2cb62
• https://git.kernel.org/stable/c/3fd6547f5b8ac99687be6d937a0321efda760597
• https://git.kernel.org/stable/c/9b55b253907e7431210483519c5ad711a37dafa1
• https://git.kernel.org/stable/c/b313e9037d98c13938740e5ebda7852929366dff
• https://git.kernel.org/stable/c/eb9c6aeb512f877cf397deb1e4526f646c70e4a7
• https://git.kernel.org/stable/c/f6e1f25fa5e733570f6d6fe37a4dfed2a0deba47
• https://git.kernel.org/stable/c/fb1f54b7d16f393b8b65d328410f78b4beea8fcc

Social Media Activity(1 post)

TheHackerWire

@thehackerwire

Apr 28, 2026

🔴 CVE-2026-31669 - Critical (9.8) In the Linux kernel, the following vulnerability has been resolved: mptcp: fix slab-use-after-free in __inet_lookup_established The ehash table lookups are lockless and rely on SLAB_TYPESAFE_BY_RCU to guarantee socket memory stability during RCU... 🔗 https://www.thehackerwire.com/vulnerability/CVE-2026-31669/ #CVE #vulnerability #infosec #cybersecurity #security #Tenda #patchstack

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