High severity · published Sep 16, 2025
CVE-2025-39823
KVM: x86: use array_index_nospec with indices that come from guest
7.8
CVSS
0.2%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: use array_index_nospec with indices that come from guest
min and dest_id are guest-controlled indices. Using array_index_nospec()
after the bounds checks clamps these values to mitigate speculative execution
side-channels.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 8% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
4.19 before 5.4.298; 5.5 before 5.10.242; 5.11 before 5.15.191; 5.16 before 6.1.150; 6.2 before 6.6.104; 6.7 before 6.12.45; +4 more · source: NVD
LI
Linux · Linux
4180bf1b655a791a0a6ef93a2ffffc762722c782 before 72777fc31aa7ab2ce00f44bfa3929c6eabbeaf48; 4180bf1b655a791a0a6ef93a2ffffc762722c782 before 31a0ad2f60cb4816e06218b63e695eb72ce74974; 4180bf1b655a791a0a6ef93a2ffffc762722c782 before d51e381beed5e2f50f85f49f6c90e023754efa12; 4180bf1b655a791a0a6ef93a2ffffc762722c782 before 33e974c2d5a82b2f9d9ba0ad9cbaabc1c8e3985f; 4180bf1b655a791a0a6ef93a2ffffc762722c782 before f49161646e03d107ce81a99c6ca5da682fe5fb69; 4180bf1b655a791a0a6ef93a2ffffc762722c782 before 67a05679621b7f721bdba37a5d18665d3aceb695; +3 more · source: vendor
DL
Debian Linux · Debian
11.0 · source: NVD
SC
SIMATIC CN 4100 · Siemens
before V5.0 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-39823
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-39823
Patch
https://git.kernel.org/stable/c/31a0ad2f60cb4816e06218b63e695eb72ce74974
Patch
https://git.kernel.org/stable/c/33e974c2d5a82b2f9d9ba0ad9cbaabc1c8e3985f
Patch
https://git.kernel.org/stable/c/67a05679621b7f721bdba37a5d18665d3aceb695
Patch
https://git.kernel.org/stable/c/72777fc31aa7ab2ce00f44bfa3929c6eabbeaf48
Patch
https://git.kernel.org/stable/c/c87bd4dd43a624109c3cc42d843138378a7f4548
Patch
https://git.kernel.org/stable/c/d51e381beed5e2f50f85f49f6c90e023754efa12
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