# CVE-2026-23266: fbdev: rivafb: fix divide error in nv3_arb() CVE-2026-23266 is fixed in 46 products on 1 platform, first by DEBIAN-CVE-2026-23266, released March 18, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-23266 - Priority: Routine - CVSS: 5.5 (Moderate) - EPSS: 0.0012 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Mar 18, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-23266 ## Description In the Linux kernel, the following vulnerability has been resolved: fbdev: rivafb: fix divide error in nv3_arb() A userspace program can trigger the RIVA NV3 arbitration code by calling the FBIOPUT_VSCREENINFO ioctl on /dev/fb*. When doing so, the driver recomputes FIFO arbitration parameters in nv3_arb(), using state->mclk_khz (derived from the PRAMDAC MCLK PLL) as a divisor without validating it first. In a normal setup, state->mclk_khz is provided by the real hardware and is non-zero. However, an attacker can construct a malicious or misconfigured device (e.g. a crafted/emulated PCI device) that exposes a bogus PLL configuration, causing state->mclk_khz to become zero. Once nv3_get_param() calls nv3_arb(), the division by state->mclk_khz in the gns calculation causes a divide error and crashes the kernel. Fix this by checking whether state->mclk_khz is zero and bailing out before doing the division. The following log reveals it: rivafb: setting virtual Y resolution to 2184 divide error: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 0 PID: 2187 Comm: syz-executor.0 Not tainted 5.18.0-rc1+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 RIP: 0010:nv3_arb drivers/video/fbdev/riva/riva_hw.c:439 [inline] RIP: 0010:nv3_get_param+0x3ab/0x13b0 drivers/video/fbdev/riva/riva_hw.c:546 Call Trace: nv3CalcArbitration.constprop.0+0x255/0x460 drivers/video/fbdev/riva/riva_hw.c:603 nv3UpdateArbitrationSettings drivers/video/fbdev/riva/riva_hw.c:637 [inline] CalcStateExt+0x447/0x1b90 drivers/video/fbdev/riva/riva_hw.c:1246 riva_load_video_mode+0x8a9/0xea0 drivers/video/fbdev/riva/fbdev.c:779 rivafb_set_par+0xc0/0x5f0 drivers/video/fbdev/riva/fbdev.c:1196 fb_set_var+0x604/0xeb0 drivers/video/fbdev/core/fbmem.c:1033 do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1188 __x64_sys_ioctl+0x122/0x190 fs/ioctl.c:856 ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 | | Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 | | Linux | kernel-default sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 | | Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.55.1.150700.17.33.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 | | Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 | | Linux | kernel-livepatch-SLE15-SP7_Update_15 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 | | Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 | | Linux | kernel-source sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 | | Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 | | Linux | kernel-uek ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-devel ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-devel ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-deprecated ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-deprecated ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-desktop ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-desktop ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-extra ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-extra ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-extra-netfilter ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-extra-netfilter ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-usb ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-usb ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-wireless ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-wireless ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-devel ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-devel ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-doc ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-doc ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-deprecated ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-deprecated ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-desktop ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-desktop ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-extra ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-extra ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-extra-netfilter ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-extra-netfilter ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-usb ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-usb ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-wireless ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-wireless ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-tools ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-tools ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-devel ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-devel ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-deprecated ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-deprecated ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-desktop ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-desktop ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-extra ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-extra ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-extra-netfilter ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-extra-netfilter ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-usb ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-usb ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-wireless ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-wireless ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.55.1 | [SUSE-SU-2026:2238-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2238-1.md) | Jun 30, 2026 | | Linux | linux Debian 12.15 (bookworm) | 6.1.164-1 | [DEBIAN-CVE-2026-23266](https://patchblox.com/security/data/fix/linux/debian-cve-2026-23266.md) | Mar 18, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.74-1 | [DEBIAN-CVE-2026-23266](https://patchblox.com/security/data/fix/linux/debian-cve-2026-23266.md) | Mar 18, 2026 | | Linux | linux Debian 14 | 6.18.13-1 | [DEBIAN-CVE-2026-23266](https://patchblox.com/security/data/fix/linux/debian-cve-2026-23266.md) | Mar 18, 2026 | --- Data as of 2026-11-09T01:18:40Z UTC. 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