CVE-2025-39823
KVM: x86: use array_index_nospec with indices that come from guest
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.
INFO
Published Date :
Sept. 16, 2025, 1:16 p.m.
Last Modified :
Sept. 16, 2025, 1:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2025-39823
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Apply the KVM array_index_nospec patch.
- Update the Linux kernel.
- Ensure indices are validated properly.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-39823.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-39823 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-39823
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-39823 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-39823 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 16, 2025
Action Type Old Value New Value Added 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. Added Reference https://git.kernel.org/stable/c/31a0ad2f60cb4816e06218b63e695eb72ce74974 Added Reference https://git.kernel.org/stable/c/33e974c2d5a82b2f9d9ba0ad9cbaabc1c8e3985f Added Reference https://git.kernel.org/stable/c/67a05679621b7f721bdba37a5d18665d3aceb695 Added Reference https://git.kernel.org/stable/c/72777fc31aa7ab2ce00f44bfa3929c6eabbeaf48 Added Reference https://git.kernel.org/stable/c/c87bd4dd43a624109c3cc42d843138378a7f4548 Added Reference https://git.kernel.org/stable/c/d51e381beed5e2f50f85f49f6c90e023754efa12 Added Reference https://git.kernel.org/stable/c/f49161646e03d107ce81a99c6ca5da682fe5fb69 Added Reference https://git.kernel.org/stable/c/f57a4bd8d6cb5af05b8ac1be9098e249034639fb