CVE-2026-52989: Linux Kernel vulnerability (CVSS 9.8)

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.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Linux Kernel≥ 5.10.250 < 5.11 · ≥ 5.15.200 < 5.16 · ≥ 6.1.163 < 6.1.175 · ≥ 6.12.70 < 6.12.91

Remediation

Fixed in

Linux Kernel≥ 5.11

Patch & vendor advisories

References

https://access.redhat.com/security/cve/CVE-2026-52989Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2492443Issue TrackingThird Party Advisory
https://git.kernel.org/stable/c/046fa5c72d15cd8e2d592e275697ea399d8f76b0Patch
https://git.kernel.org/stable/c/3df42a854686fa06484e37ac1a3931c8e3e3453cPatch
https://git.kernel.org/stable/c/c2a11441538bdbbc5aa003f190995eba93a89b88Patch
https://git.kernel.org/stable/c/d7c8f95f599b3b38a717d2e771c3f8c174f657c3Patch
https://git.kernel.org/stable/c/ea8e356acb165cb1fd75537a52e1f66e5e76c538Patch
https://git.kernel.org/stable/c/f9204a2b78dd18374d3bcf9bf93d9021ce22de1bPatch
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52989.jsonThird Party Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-52989 being actively exploited?

CVE-2026-52989 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.36%.

How severe is CVE-2026-52989?

CVE-2026-52989 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.36% probability of exploitation.

Which products are affected by CVE-2026-52989?

Affected products include Linux Kernel.

How do I fix CVE-2026-52989?

Upgrade affected software to a fixed version, for example Linux Kernel 5.11 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

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