In-Place Cryptographic Transformation Vulnerability in Linux Kernel

CVE-2026-63831

What is CVE-2026-63831?

The Linux kernel contains a vulnerability that arises from in-place cryptographic transformations of shared socket buffer (skb) data. This occurs in several cryptographic functions, such as llsec_do_encrypt_unauth() and llsec_do_decrypt_unauth(), where both the source and destination of cryptographic operations reference the same data buffer. This design flaw can lead to silent data corruption, potential use-after-free conditions, and kernel crashes during concurrent traffic, especially when security features are enabled. A resolution has been implemented that involves using skb_cow_data() to ensure that the skb data area is not shared before any in-place cryptographic operations are executed.

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