CVE-2026-64524: Linux kernel · drm/hyperv: validate resolution_count and fix WIN8 fallback
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.7 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 28 Oct 2026, 11:48 UTC
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +68
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 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.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-8618-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8663-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8664-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8903-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
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 incorporated into Linux kernel versions 5.15.0-1117.124~20.04.1 and later. Users and administrators should update affected Linux kernel versions to these fixed releases or newer to remediate the vulnerability. No additional mitigation is required beyond applying the official fix.
Description
CVE-2026-64524 is a high-severity vulnerability in the Linux kernel's drm/hyperv subsystem. It involves improper validation of the resolution_count in SYNTHVID_RESOLUTION_RESPONSE messages, allowing out-of-bounds array access. Additionally, a fallback mechanism for Windows 8 resolution probing was flawed, causing framebuffer creation failures. This issue has been fixed in Linux kernel versions 5.15.0-1117.124~20.04.1 and later.
References
- ubuntu.com/security/CVE-2026-64524 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64524 (opens in a new tab)
- git.kernel.org/linus/13d33b9ef67066c77c84273fac5a1d3fde3533d1 (opens in a new tab)
- git.kernel.org/stable/c/13d33b9ef67066c77c84273fac5a1d3fde3533d1 (opens in a new tab)
- git.kernel.org/stable/c/1fb565b77b8f44afabb02de6310065f109d89e94 (opens in a new tab)
- git.kernel.org/stable/c/8a114b25b5521eae451b13bce98ae978624962e5 (opens in a new tab)
- git.kernel.org/stable/c/96f7de3172d4aa878b7f87173b2b3507c350fcd6 (opens in a new tab)
- git.kernel.org/stable/c/9c698b2c43c2667c34f5336bf46ad5786216ac2a (opens in a new tab)
- git.kernel.org/stable/c/a321c908f2eeea01539668eb270d074d9b88e490 (opens in a new tab)
- git.kernel.org/stable/c/bc573752f3dac0d1ab8df7078c1851bc76717653 (opens in a new tab)
- ubuntu.com/security/notices/USN-8618-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8663-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8664-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)