CVE-2026-64235: Linux kernel · x86/ftrace: Relocate %rip-relative percpu refs in dynamic trampolines
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.1 High · fixed in 7.0.0-28.28~24.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 25% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-28.28~24.04.1, 7.0.0-1016.16~24.04.1, 7.0.0-28.28 +12
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 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
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
An official patch is available and should be applied to affected Linux kernel versions. The fix correctly relocates the %rip-relative per-CPU references in dynamic trampolines to prevent the kernel crash. Users should update to the patched kernel versions as per the vendor advisory. No additional mitigations are specified or required beyond applying the official fix.
Description
A vulnerability in the Linux kernel's x86 ftrace subsystem was resolved, addressing a crash caused by incorrect relocation of %rip-relative per-CPU references in dynamic trampolines when CONFIG_CALL_DEPTH_TRACKING is enabled on certain x86 platforms affected by retbleed. This flaw leads to a kernel page fault and panic when registering a dynamic ftrace trampoline. The issue stems from the call depth accounting code using %rip-relative addressing without proper runtime adjustment, causing invalid memory access. A fix was implemented to correctly relocate the call depth accounting instruction at runtime.
References
- ubuntu.com/security/CVE-2026-64235 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64235 (opens in a new tab)
- git.kernel.org/linus/a17dc12bfed8868e6a86f3b45c16065a70641acb (opens in a new tab)
- git.kernel.org/stable/c/8093442a2d1d4b42b9340a86023ccb2afb30b93a (opens in a new tab)
- git.kernel.org/stable/c/9edff632ca216169846f8a63a5a3dc467e239c7a (opens in a new tab)
- git.kernel.org/stable/c/a17dc12bfed8868e6a86f3b45c16065a70641acb (opens in a new tab)
- git.kernel.org/stable/c/d59cc66b702757e3c5a711e78a38583eac0c2738 (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)