GHSA-c589-8xvr-7cm3 · 深刻度： medium — In the Linux kernel, the following vulnerability has been resolved: fbdev: rivafb: fix divide...
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
総合評価: CVE-2026-23266 は低リスク（22.7/100）。CVSS 深刻度は中。悪用される可能性が高い（EPSS 0.11%、2 パーセンタイル） 推奨対応: 悪用情報と EPSS の推移を監視し、必要に応じて優先度を見直してください。
リスクは変動します。再評価に基づき、本ページの表示内容を更新しています。
EPSS は日次で悪用されやすさの相対度合いを推定します。パーセンタイルは採点済み CVE の中での相対位置（高いほど相対的に深刻）を示します。
| # | 日付 | 旧 EPSS スコア | 新 EPSS スコア | Δ（新 − 旧） |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.02% | 0.11% | +0.09% |
| 2 | 2026-03-19 | — | 0.02% | — |
EPSS の全履歴 （全 2 件）
この CVE の CVSS 指標。
| ベーススコア | バージョン | 深刻度 | ベクトル | 悪用しやすさ | 影響 | スコアの出典 |
|---|---|---|---|---|---|---|
| 5.5 | 3.1 | MEDIUM |
|
1.8 | 3.6 | [email protected] |
GHSA-c589-8xvr-7cm3 · 深刻度： medium — In the Linux kernel, the following vulnerability has been resolved: fbdev: rivafb: fix divide...
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2026-23266 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2026-23266 |
redhat
|
— | — | https://access.redhat.com/security/cve/CVE-2026-23266 |
suse
|
medium | CVE-2026-23266 severity moderate: SUSE including 26 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 193 product×package rows across 34 product lines (SUSE Linux Enterprise High Availability Extension 15 SP7, SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, … (34 product lines)): Known Not Affected 193. | https://www.suse.com/security/cve/CVE-2026-23266/ |
ubuntu
|
medium | CVE-2026-23266 medium priority: Ubuntu including 157 source packages (linux, linux-allwinner-5.19, …), 1256 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): DNE 871, ignored 173, needed 128, released 83, not-affected 1. | https://ubuntu.com/security/CVE-2026-23266 |
| ベンダー | 製品 | バージョン | 生の CPE |
|---|---|---|---|
| linux | linux_kernel | >= 2.6.12.1, < 5.10.251 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 5.11, < 5.15.201 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 5.16, < 6.1.164 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 6.2, < 6.6.127 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 6.7, < 6.12.74 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 6.13, < 6.18.13 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 6.19, < 6.19.3 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | 2.6.12 | cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:* |
| linux | linux_kernel | 2.6.12 | cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:* |
| linux | linux_kernel | 2.6.12 | cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:* |
| linux | linux_kernel | 2.6.12 | cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:* |
| linux | linux_kernel | 2.6.12 | cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:* |