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 26 Oct 2026, 12:55 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- 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 +66
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.
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 included in updated Linux kernel packages. Users and administrators should apply the official Linux kernel updates that include the fix for this vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Description
A vulnerability in the Linux kernel's drm/hyperv subsystem involved improper validation of resolution_count in SYNTHVID_RESOLUTION_RESPONSE messages, leading to potential out-of-bounds array access. Additionally, fallback handling for screen resolution probing on Windows 8 and Windows 10 was corrected to prevent framebuffer creation failures. This issue affects multiple Linux kernel versions prior to 7.0.0-28.28 and related builds. A patch addressing these issues is available. The CVSS score is 7.7, indicating medium severity. No known exploits have been reported in the wild.
References
- nvd.nist.gov/vuln/detail/CVE-2026-64524 (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/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)
- 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)