CVE-2025-39823
Not scored
KVM: x86: use array_index_nospec with indices that come from guest
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.
Exploit probability
0.2%
Published
September 16, 2025
Required by
Not available
Last source change
August 12, 2026
02 / AFFECTED SOFTWARE
Affected packages
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
Open Source Vulnerabilities
CVE-2025-39823
View original source
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.
05 / REFERENCES
Further evidence
- https://cert-portal.siemens.com/productcert/html/ssa-032379.html
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/31a0ad2f60cb4816e06218b63e695eb72ce74974
- https://git.kernel.org/stable/c/33e974c2d5a82b2f9d9ba0ad9cbaabc1c8e3985f
- https://git.kernel.org/stable/c/67a05679621b7f721bdba37a5d18665d3aceb695
- https://git.kernel.org/stable/c/72777fc31aa7ab2ce00f44bfa3929c6eabbeaf48
- https://git.kernel.org/stable/c/c87bd4dd43a624109c3cc42d843138378a7f4548
- https://git.kernel.org/stable/c/d51e381beed5e2f50f85f49f6c90e023754efa12
- https://git.kernel.org/stable/c/f49161646e03d107ce81a99c6ca5da682fe5fb69
- https://git.kernel.org/stable/c/f57a4bd8d6cb5af05b8ac1be9098e249034639fb
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39823.json
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
- https://nvd.nist.gov/vuln/detail/CVE-2025-39823