CVE-2026-52989

CVE-2026-52989 is a critical-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-908.

Key facts

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.

Frequently asked questions

What is CVE-2026-52989?
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.
How severe is CVE-2026-52989?
CVE-2026-52989 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-52989 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-52989?
CVE-2026-52989 primarily affects Linux Linux Kernel. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-52989?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-52989 have an EU (EUVD) identifier?
Yes. CVE-2026-52989 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38857.
When was CVE-2026-52989 published?
CVE-2026-52989 was published on 2026-06-24 and last updated on 2026-08-21.

References

Affected products (3)

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