CVE-2026-52989: linux Use of Uninitialized Resource

Vulnerability summary

CVE-2026-52989 is a critical (CVSS 9.8) Use of Uninitialized Resource vulnerability in linux. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 27.9% of scored vulnerabilities.

Timeline

1. 24-06-2026
   PublishedVulnerability first disclosed.
2. 24-08-2026
   Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: propagate nvmet_tcp_build_pdu_iovec() errors to its callers Currently, when nvmet_tcp_build_pdu_iovec() detects an out-of-bounds PDU length or offset, it triggers nvmet_tcp_fatal_error(cmd->queue) and returns early. However, because the function returns void, the callers are entirely unaware that a fatal error has occurred and that the cmd->recv_msg.msg_iter was left uninitialized. Callers such as nvmet_tcp_handle_h2c_data_pdu() proceed to blindly overwrite the queue state with queue->rcv_state = NVMET_TCP_RECV_DATA Consequently, the socket receiving loop may attempt to read incoming network data into the uninitialized iterator. Fix this by shifting the error handling responsibility to the callers.

• CWE-908Use of Uninitialized ResourceThe product uses or accesses a resource that has not been initialized.
• CWE-390Detection of Error Condition Without ActionThe product detects a specific error, but takes no actions to handle the error.