Local denial of service via fbcon race
Published Dec 16, 2025 · Updated Dec 16, 2025
A race condition in Linux kernel fbcon setup allows local users to crash affected systems by racing VGA output switching. vga_switcheroo_client_fb_set() can run before register_framebuffer() assigns struct fb_info.node, so fbcon_remap_all() passes -1 to set_con2fb_map() as an array index. Reachability requires hybrid graphics using amdgpu, i915, nouveau, or radeon with vga_switcheroo; the documented consequence is an out-of-bounds access and service interruption.
Summary
What happened
A race condition in Linux kernel fbcon setup allows local users to crash affected systems by racing VGA output switching. vga_switcheroo_client_fb_set() can run before register_framebuffer() assigns struct fb_info.node, so fbcon_remap_all() passes -1 to set_con2fb_map() as an array index. Reachability requires hybrid graphics using amdgpu, i915, nouveau, or radeon with vga_switcheroo; the documented consequence is an out-of-bounds access and service interruption.
The record
- CVE
- CVE-2025-68296
- Published
- Dec 16, 2025
- Updated
- Dec 16, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-367, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 16, 2025CVE publishedPublication date reported by the CVE source.
- Dec 16, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2.6.34
- Affected versionversion=6a9ee8af344e3bd7dbd61e67037096cdf7f83289 <05814c389b53d2f3a0b9eeb90ba7a05ba77c4c2a
- Affected versionversion=6a9ee8af344e3bd7dbd61e67037096cdf7f83289 <482330f8261b4bea8146d9bd69c1199e5dfcbb5c
- Affected versionversion=6a9ee8af344e3bd7dbd61e67037096cdf7f83289 <eb76d0f5553575599561010f24c277cc5b31d003
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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