KVM: x86: use array_index_nospec with indices that come from guest
Priority LOW 33CWE-129Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 3 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-129 and the CVSS impact.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00181 7th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.4.298, 5.10.242, 5.15.191 +5Red Hat: 3 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 4.19 and later | 5.4.298, 5.10.242, 5.15.191, 6.1.150, 6.6.104, 6.12.45, 6.16.5, 6.17 | Patch available | CNA |
- Linux VendorLinux Affected 4.19 and later Fixed in 5.4.298, 5.10.242, 5.15.191, 6.1.150, 6.6.104, 6.12.45, 6.16.5, 6.17 Patch available CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.19 to before 5.4.298; 5.5 to before 5.10.242; 5.11 to before 5.15.191; 5.16 to before 6.1.150; 6.2 to before 6.6.104; 6.7 to before 6.12.45; 6.13 to before 6.16.5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* | 6.17 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* | 6.17 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:* | 6.17 rc3 | Vulnerable | Linux |
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | 11.0 | Vulnerable | Debian |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.19 to before 5.4.298; 5.5 to before 5.10.242; 5.11 to before 5.15.191; 5.16 to before 6.1.150; 6.2 to before 6.6.104; 6.7 to before 6.12.45; 6.13 to before 6.16.5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* Versions 6.17 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* Versions 6.17 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:* Versions 6.17 rc3 Vulnerable ·Linux
- cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.4.298, 5.10.242, 5.15.191, 6.1.150, 6.6.104, 6.12.45, 6.16.5, 6.17
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 2 products
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2025-39823
- 2026-10-03 Alias added: GHSA-g6f5-85j8-c4fr
- 2026-11-05 CISA SSVC decision points changed
References
Patch 8
- https://git.kernel.org/stable/c/72777fc31aa7ab2ce00f44bfa3929c6eabbeaf48
- https://git.kernel.org/stable/c/31a0ad2f60cb4816e06218b63e695eb72ce74974
- https://git.kernel.org/stable/c/d51e381beed5e2f50f85f49f6c90e023754efa12
- https://git.kernel.org/stable/c/33e974c2d5a82b2f9d9ba0ad9cbaabc1c8e3985f
- https://git.kernel.org/stable/c/f49161646e03d107ce81a99c6ca5da682fe5fb69
- https://git.kernel.org/stable/c/67a05679621b7f721bdba37a5d18665d3aceb695
- https://git.kernel.org/stable/c/f57a4bd8d6cb5af05b8ac1be9098e249034639fb
- https://git.kernel.org/stable/c/c87bd4dd43a624109c3cc42d843138378a7f4548
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2025-39823 · CVE Program
- CVE-2025-39823 · NVD
- FIRST EPSS
- GHSA-g6f5-85j8-c4fr · GitHub Advisory Database · CC BY 4.0
- CVE-2025-39823 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences