PT-2026-26126 · Linux · Linux Kernel

Published 2025-12-07 · Updated 2026-04-20 · CVE-2026-23266

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 5.18.0-rc1+

Description The Linux kernel contains a flaw within the RIVA NV3 arbitration code. A userspace program can trigger this code by calling the FBIOPUT VSCREENINFO ioctl on /dev/fb*. The driver recalculates FIFO arbitration parameters in the nv3 arb() function, using state->mclk khz (derived from the PRAMDAC MCLK PLL) as a divisor without prior validation. An attacker can provide a malicious or misconfigured device that sets state->mclk khz to zero, leading to a divide error and kernel crash when nv3 get param() calls nv3 arb(). The vulnerable code is located in drivers/video/fbdev/riva/riva hw.c. The issue occurs during the calculation of the gns value within the nv3 arb() function.

Recommendations Update to a version newer than 5.18.0-rc1+.

Exploit

Fix

Divide By Zero

Weakness Enumeration

CWE-369

Related Identifiers

BDU:2026-03570

CVE-2026-23266

OPENSUSE-SU-2026:20826-1

SUSE-SU-2026:21841-1

SUSE-SU-2026:21845-1

SUSE-SU-2026:21860-1

Affected Products

Linux Kernel

References · 26

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23266.json · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-23266 · Security Note
• https://git.kernel.org/stable/c/78daf5984d96edec3b920c72a93bd6821b8710b7 · Patch
• https://osv.dev/vulnerability/BELL-CVE-2026-23266 · Vendor Advisory
• https://git.kernel.org/stable/c/526460a96c5443e2fc0fd231edd1f9c49d2de26b · Patch
• https://git.kernel.org/stable/c/0209e21e3c372fa2da04c39214bec0b64e4eb5f4 · Patch
• https://ubuntu.com/security/CVE-2026-23266 · Vendor Advisory
• https://osv.dev/vulnerability/ROOT-OS-UBUNTU-2404-CVE-2026-23266 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-23266 · Vendor Advisory
• https://git.kernel.org/stable/c/73f0391e92d404da68f7484e57c106c5e673dc7e · Patch
• https://bdu.fstec.ru/vul/2026-03570 · Security Note
• https://git.kernel.org/stable/c/9efa0dc46270a8723c158c64afbcf1dead72b28c · Patch
• https://git.kernel.org/stable/c/ec5a58f4fd581875593ea92a65485e1906a53c0f · Patch
• https://osv.dev/vulnerability/ROOT-OS-UBUNTU-2204-CVE-2026-23266 · Vendor Advisory
• https://git.kernel.org/stable/c/52916878db2b8e3769743a94484729f0844352df · Patch