CVE-2026-23266

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2026-03-18. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity55% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
2%
KEV
Not listed

Published

March 18, 2026

Last Modified

June 17, 2026

Advisory Details (8)

Auto-updated Aug 6, 2026
No patch confirmed yet.
generic

fbdev: rivafb: fix divide error in nv3_arb() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ec5a58f4fd581875593ea92a65485e1906a53c0f
generic

fbdev: rivafb: fix divide error in nv3_arb() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9efa0dc46270a8723c158c64afbcf1dead72b28c
generic

fbdev: rivafb: fix divide error in nv3_arb() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/78daf5984d96edec3b920c72a93bd6821b8710b7
generic

fbdev: rivafb: fix divide error in nv3_arb() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/73f0391e92d404da68f7484e57c106c5e673dc7e
generic

fbdev: rivafb: fix divide error in nv3_arb() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/52916878db2b8e3769743a94484729f0844352df
generic

fbdev: rivafb: fix divide error in nv3_arb() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/526460a96c5443e2fc0fd231edd1f9c49d2de26b
generic

fbdev: rivafb: fix divide error in nv3_arb() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3e4cbd1d46c246dfa684c8e9d8c20ae0b960c50a
generic

fbdev: rivafb: fix divide error in nv3_arb() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0209e21e3c372fa2da04c39214bec0b64e4eb5f4

Vendor Advisories for CVE-2026-23266(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
linuxKernel @ 5.10.251—osv

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (49 versions)5.10.251-1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (47 versions)6.1.164-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.73-1~bpo12+1 (13 versions)6.12.74-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 6.18~rc7-1~exp1 (102 versions)6.18.13-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(23)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 4× in last 7d / 23× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 176 total refreshes for this CVE.

  1. 2026-09-18 19:27 UTCEPSS rescore
  2. 2026-09-16 14:07 UTCEPSS rescore
  3. 2026-09-16 05:15 UTCEPSS rescore
  4. 2026-09-13 16:47 UTCEPSS rescore
  5. 2026-09-11 14:52 UTCEPSS rescore
  6. 2026-09-10 09:34 UTCEPSS rescore
  7. 2026-09-07 16:01 UTCEPSS rescore
  8. 2026-09-06 13:47 UTCEPSS rescore
  9. 2026-09-06 13:47 UTCEPSS rescore
  10. 2026-09-04 05:06 UTCEPSS rescore
  11. 2026-09-02 18:08 UTCOSV refresh
  12. 2026-09-02 14:11 UTCEPSS rescore
  13. 2026-09-01 13:53 UTCEPSS rescore
  14. 2026-09-01 04:39 UTCEPSS rescore
  15. 2026-08-30 19:17 UTCEPSS rescore
  16. 2026-08-30 01:22 UTCEPSS rescore
  17. 2026-08-28 21:41 UTCEPSS rescore
  18. 2026-08-27 14:25 UTCEPSS rescore
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  20. 2026-08-25 13:48 UTCEPSS rescore
  21. 2026-08-23 00:19 UTCEPSS rescore
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  24. 2026-08-19 17:03 UTCEPSS rescore
  25. 2026-08-18 13:48 UTCEPSS rescore
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  1. 2026-08-17 13:47 UTCEPSS rescore
  2. 2026-08-16 14:56 UTCEPSS rescore
  3. 2026-08-16 11:15 UTCEG score recompute
  4. 2026-08-16 11:15 UTCVendor advisory
  5. 2026-08-16 11:15 UTCGHSA enrichment
  6. 2026-08-16 02:14 UTCEPSS rescore
  7. 2026-08-15 01:30 UTCEPSS rescore
  8. 2026-08-14 07:24 UTCEG score recompute
  9. 2026-08-14 07:24 UTCVendor advisory
  10. 2026-08-14 07:24 UTCGHSA enrichment
  11. 2026-08-13 22:00 UTCEPSS rescore
  12. 2026-08-12 22:56 UTCEG score recompute
  13. 2026-08-12 22:56 UTCVendor advisory
  14. 2026-08-12 22:56 UTCGHSA enrichment
  15. 2026-08-12 13:50 UTCEPSS rescore
  16. 2026-08-11 21:31 UTCEG score recompute
  17. 2026-08-11 21:31 UTCVendor advisory
  18. 2026-08-11 21:31 UTCGHSA enrichment
  19. 2026-08-11 13:42 UTCEPSS rescore
  20. 2026-08-11 00:00 UTCEPSS rescore
  21. 2026-08-10 08:23 UTCEG score recompute
  22. 2026-08-10 08:23 UTCVendor advisory
  23. 2026-08-10 08:23 UTCGHSA enrichment
  24. 2026-08-09 13:46 UTCEPSS rescore
  25. 2026-08-09 06:58 UTCVendor advisory
  26. 2026-08-09 06:58 UTCGHSA enrichment
  27. 2026-08-07 17:31 UTCEG score recompute
  28. 2026-08-07 17:31 UTCVendor advisory
  29. 2026-08-07 17:31 UTCGHSA enrichment
  30. 2026-08-06 13:46 UTCEPSS rescore
  31. 2026-08-06 01:37 UTCEG score recompute
  32. 2026-08-06 01:37 UTCVendor advisory
  33. 2026-08-06 01:37 UTCGHSA enrichment
  34. 2026-08-05 19:17 UTCEPSS rescore
  35. 2026-08-04 15:10 UTCEPSS rescore
  36. 2026-08-04 10:38 UTCEPSS rescore
  37. 2026-08-04 00:48 UTCEG score recompute
  38. 2026-08-04 00:48 UTCVendor advisory
  39. 2026-08-04 00:48 UTCGHSA enrichment
  40. 2026-08-03 10:35 UTCEPSS rescore
  41. 2026-08-02 16:41 UTCEG score recompute
  42. 2026-08-02 16:41 UTCVendor advisory
  43. 2026-08-02 16:41 UTCGHSA enrichment
  44. 2026-08-02 02:26 UTCEPSS rescore
  45. 2026-08-01 04:15 UTCEPSS rescore
  46. 2026-07-30 01:30 UTCEPSS rescore
  47. 2026-07-27 14:13 UTCEPSS rescore
  48. 2026-07-25 14:17 UTCEPSS rescore
  49. 2026-07-25 14:17 UTCEPSS rescore
  50. 2026-07-24 14:17 UTCEPSS rescore
  51. 2026-07-23 14:18 UTCEPSS rescore
  52. 2026-07-23 14:18 UTCEPSS rescore
  53. 2026-07-23 03:06 UTCEG score recompute
  54. 2026-07-22 14:08 UTCEPSS rescore
  55. 2026-07-21 15:24 UTCEPSS rescore
  56. 2026-07-21 15:24 UTCEPSS rescore
  57. 2026-07-20 17:08 UTCEPSS rescore
  58. 2026-07-19 14:31 UTCEPSS rescore
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  60. 2026-07-19 02:29 UTCEPSS rescore
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  62. 2026-07-18 10:04 UTCEPSS rescore
  63. 2026-07-18 10:04 UTCEPSS rescore
  64. 2026-07-17 07:46 UTCOSV refresh
  65. 2026-07-16 17:03 UTCEPSS rescore
  66. 2026-07-16 17:03 UTCEPSS rescore
  67. 2026-07-15 16:57 UTCEPSS rescore
  68. 2026-07-15 16:57 UTCEPSS rescore
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  71. 2026-07-13 22:30 UTCEPSS rescore
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  74. 2026-07-12 05:46 UTCEPSS rescore
  75. 2026-07-12 05:46 UTCEPSS rescore

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-23266?
CVE-2026-23266 is a medium vulnerability published on March 18, 2026. 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…
When was CVE-2026-23266 disclosed?
CVE-2026-23266 was first published in the National Vulnerability Database on March 18, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-23266 actively exploited?
CVE-2026-23266 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 98.3% of all scored CVEs.
What is the CVSS score of CVE-2026-23266?
CVE-2026-23266 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-23266?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-23266, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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