CVE-2026-74611
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
In the Linux kernel, in TLS RX, during optimistic TLS 1.3 zero-copy attempt, the msg_iter pointer is not restored after a failed attempt, which can lead to overwriting data in the receiver's buffer.
Risk Assessment
Possible overwriting of user data in the receiver's buffer, leading to data corruption or application malfunction. A remote attacker could exploit this.
Recommendation
Install a kernel patch that restores msg_iter before retrying without zero-copy.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: tls: rx: restore msg_iter before TLS 1.3 optimistic retry tls_decrypt_sg() advances msg->msg_iter when it maps user pages for the optimistic TLS 1.3 zero-copy path. If the decrypted record turns out not to be unpadded application data, tls_decrypt_sw() retries into a kernel skb, but leaves the iterator advanced. The subsequent copy from the skb then writes decrypted bytes again at a later point in the caller iovecs while recvmsg() reports only the post-retry length. A TLS peer can trigger this after the receiver enables TLS_RX_EXPECT_NO_PAD. Revert the iterator by the number of bytes consumed by the optimistic mapping before retrying without zero-copy. Add a selftest which sends a TLS 1.3 control record with TLS_RX_EXPECT_NO_PAD enabled and verifies that recvmsg() does not overwrite later iovecs beyond the returned length.