CVE-2026-64534
Linux kernel vulnerability
- Published27 Jul 2026
Description
In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path In nvmet_tcp_try_recv_ddgst(), when a data digest mismatch is detected, nvmet_req_uninit() is called unconditionally. However, if the command arrived via the nvmet_tcp_handle_req_failure() path, nvmet_req_init() had returned false and percpu_ref_tryget_live() was never executed. The unconditional percpu_ref_put() inside nvmet_req_uninit() then causes a refcount underflow, leading to a WARNING in percpu_ref_switch_to_atomic_rcu, a use-after-free diagnostic, and eventually a permanent workqueue deadlock. Check cmd->flags & NVMET_TCP_F_INIT_FAILED before calling nvmet_req_uninit(), matching the existing pattern in nvmet_tcp_execute_request().
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HRemediation
No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.
References
- https://git.kernel.org/stable/c/22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf
- https://git.kernel.org/stable/c/2ed3c9d955e8cd6361f130623baa664a75fb345f
- https://git.kernel.org/stable/c/4606467a75cfc16721937272ed29462a750b60c8
- https://git.kernel.org/stable/c/ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e
- https://git.kernel.org/stable/c/c7874dad84b20433c0fe3919f291a762d40de08b
- https://git.kernel.org/stable/c/d306da8833e75f669d93424fd84940236f3850bc
- https://git.kernel.org/stable/c/e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1
Frequently asked
Is CVE-2026-64534 being actively exploited?
CVE-2026-64534 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.42%.
How severe is CVE-2026-64534?
CVE-2026-64534 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.42% probability of exploitation.
How do I fix CVE-2026-64534?
Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-64534 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.