VulnerabilityPublished 19 Jul 2026Updated 28 Oct 2026

CVE-2026-63826: Linux kernel · fbdev: fix use-after-free in store_modes()

Affects Linux kernelSource GCVE Database

Not known to be exploited · fixed in 6.8.0-147.147 : update Linux kernel when convenient.

Data as of 28 Oct 2026, 12:34 UTC

Severity

Low

Rated by Threat Radar · No CVSS score from NVD or the CNA

Patch: Available – fixed in 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1012.12~24.04.1 +28

Exploitation evidence

Disclosed: evidence found.
CVE published 19 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Patches and advisories

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=resolute`Other threats	Affected <7.0.0-31.31	Fixed in 7.0.0-31.31
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=resolute`Other threats	Affected <7.0.0-1012.12	Fixed in 7.0.0-1012.12
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=resolute`Other threats	Affected <7.0.0-1014.14	Fixed in 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resolute`Other threats	Affected <7.0.0-1013.13	Fixed in 7.0.0-1013.13
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=resolute`Other threats	Affected <7.0.0-1011.11	Fixed in 7.0.0-1011.11
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=resolute`Other threats	Affected <7.0.0-1006.7	Fixed in 7.0.0-1006.7

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available and has been applied in multiple Linux kernel versions including 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1012.12~24.04.1, and others. Users and administrators should update to these fixed kernel versions to remediate the vulnerability. No additional mitigation actions are required beyond applying the official kernel updates.

Description

A use-after-free vulnerability was identified and fixed in the Linux kernel's framebuffer device (fbdev) subsystem within the store_modes() function. The flaw occurs because pointers referencing a freed modelist are not properly cleared, leading to potential use-after-free reads when accessing framebuffer modes. This issue affects multiple Linux kernel versions prior to the fixed releases. The vulnerability is rated as low severity and no known exploits are reported in the wild. Official patches are available in several Linux kernel versions.

Impact

The vulnerability allows use-after-free reads in the framebuffer device subsystem, which could lead to system instability or potential information disclosure. However, the severity is rated low and no known exploit code or active exploitation has been reported. The impact is limited to local userspace interactions with framebuffer modes and does not indicate remote code execution or privilege escalation.

Summary

The Linux kernel's fbdev subsystem had a use-after-free vulnerability in the store_modes() function, which replaces a framebuffer's modelist with modes from userspace. After freeing the old modelist, two pointers (fb_display[i].mode and fb_info->mode) still referenced the freed memory. fb_display[i].mode is only updated for consoles mapped to the framebuffer, leaving unmapped consoles with stale pointers. fb_info->mode is not updated by store_modes(), leaving it pointing to freed memory. Subsequent operations such as FBIOPUT_VSCREENINFO ioctl or reading the mode sysfs attribute dereference these stale pointers, causing use-after-free reads. The fix involves clearing these pointers before freeing the list and calling fbcon_delete_modelist() from store_modes() to clear all stale fb_display[i].mode pointers. Multiple affected kernel versions have been patched.

GCVE source: db.gcve.eu
OSV ID: UBUNTU-CVE-2026-63826
Osv Schema Version: 1.7.0
Ecosystems: Ubuntu:Pro:14.04:LTS, Ubuntu:Pro:16.04:LTS, Ubuntu:16.04:LTS, Ubuntu:Pro:FIPS-updates:16.04:LTS, Ubuntu:Pro:FIPS:16.04:LTS, Ubuntu:Pro:18.04:LTS, Ubuntu:18.04:LTS, Ubuntu:Pro:FIPS-updates:18.04:LTS, Ubuntu:Pro:FIPS:18.04:LTS, Ubuntu:Pro:20.04:LTS, Ubuntu:20.04:LTS, Ubuntu:Pro:FIPS-updates:20.04:LTS, Ubuntu:Pro:FIPS:20.04:LTS, Ubuntu:22.04:LTS, Ubuntu:Nvidia-BlueField:22.04:LTS, Ubuntu:Pro:Realtime:22.04:LTS, Ubuntu:Pro:FIPS-preview:22.04:LTS, Ubuntu:Pro:FIPS-updates:22.04:LTS, Ubuntu:24.04:LTS, Ubuntu:Nvidia-BlueField:24.04:LTS, Ubuntu:Pro:Realtime:24.04:LTS, Ubuntu:Pro:FIPS-updates:24.04:LTS, Ubuntu:26.04:LTS

References

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