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CVE-2025-39950 is a Linux kernel networking vulnerability in the TCP subsystem affecting the TCP Authentication Option implementation. During a connect() operation on a TCP socket configured with a TCP-AO key and with TCP_REPAIR enabled, tcp_connect() can reach tcp_finish_connect() with a NULL skb pointer. That NULL pointer is then passed into tcp_ao_finish_connect() in net/ipv4/tcp_ao.c, where the code dereferences tcp_hdr(skb)->seq without first validating that skb is non-NULL. This results in a kernel NULL pointer dereference. The flaw was introduced in Linux kernel 6.7 and fixed by adding an explicit NULL check before dereferencing skb.
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A NULL pointer dereference in the Linux kernel TCP subsystem caused by interaction between TCP-AO and TCP_REPAIR during connect(), where a NULL skb is passed and dereferenced without validation. The content states unprivileged users can trigger it.
A Linux kernel TCP subsystem NULL pointer dereference triggered by combining TCP-AO and TCP_REPAIR and issuing connect(), allowing unprivileged users to crash or disrupt the system.
A Linux kernel NULL pointer dereference vulnerability in tcp_ao_finish_connect() triggered when using TCP-AO together with TCP_REPAIR during connect(), due to dereferencing a NULL skb pointer.
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Cross-references every affected SKU, including bundled OEM variants.
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