High severity · published Sep 11, 2026
CVE-2026-89743
misc: nsm: bound the device-reported response length
7.7
CVSS
0.1%
EPSS
No
On KEV
Description
In 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 vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
b9873755a6c8ccfce79094c4dce9efa3ecb1a749 before 339f19b9a6171289b0e797deb8bda80b9a1fcc30; b9873755a6c8ccfce79094c4dce9efa3ecb1a749 before 29e634a18957acda11383a15ab98a91c4ae9e294; b9873755a6c8ccfce79094c4dce9efa3ecb1a749 before 2aa0fb9c96f894a9c179a48e7522ea6705800adf; b9873755a6c8ccfce79094c4dce9efa3ecb1a749 before 808e530654a5354e6df78863a5d61e4d44e67235; 6.8 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89743
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-89743
git.kernel.org
https://git.kernel.org/stable/c/29e634a18957acda11383a15ab98a91c4ae9e294
git.kernel.org
https://git.kernel.org/stable/c/2aa0fb9c96f894a9c179a48e7522ea6705800adf
git.kernel.org
https://git.kernel.org/stable/c/339f19b9a6171289b0e797deb8bda80b9a1fcc30
git.kernel.org
https://git.kernel.org/stable/c/808e530654a5354e6df78863a5d61e4d44e67235
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