CVE-2026-89743
HighIn the Linux kernel, the following vulnerability has been resolved: misc: nsm: bound the device-reported response length nsm_sendrecv_msg_locked() stores the virtqueue used-ring length reported by the NSM device into msg->resp.len without bounding it to the response buffer. A malicious or buggy backend can report a length larger than the response buffer; parse_resp_raw() then copies that many bytes out of the fixed buffer to user space, disclosing adjacent kernel heap (an out-of-bounds read). The request path already floors its length in fill_req_raw(); the response path lacks the symmetric check. Clamp the stored length to the size of the response buffer. Well-behaved devices report no more than the posted buffer size, so conforming traffic is unaffected.
CVSS 3.1 score
7.7
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Affected versions
Linux kernel versions
6.8
and later are affected. Fixed in
6.12.109,
6.18.50,
7.2.4,
7.3-rc1
and their respective stable series.
References
4 totalFrequently asked questions
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What is CVE-2026-89743?
CVE-2026-89743 is a High severity Linux kernel vulnerability with a CVSS score of 7.7 out of 10 . It affects Linux kernel versions from 6.8 onward and has been patched in 6.12.109, 6.18.50, 7.2.4 and others. CVE-2026-89743 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2026-89743?
CVE-2026-89743 has a CVSS score of 7.7 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H. -
Is there a patch available for CVE-2026-89743?
Yes. CVE-2026-89743 has been patched. Fixed versions include 6.12.109, 6.18.50, 7.2.4 and others. If you are running Linux kernel 6.8 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-89743 actively exploited?
No. CVE-2026-89743 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.