CVE-2026-46315: Linux kernel · io_uring/waitid: clear waitid info before copying it to userspace IORING_OP_WAITID
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 6.8.0-1064.67~22.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1064.67~22.04.1, 6.8.0-1067.75~22.04.1, 6.8.0-1065.72~22.04.1 +41
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 9 Jun 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 should be applied by updating to the fixed Linux kernel versions as listed in the Ubuntu security advisories USN-8566-1 and USN-8568-1. After updating, a system reboot is required. Due to ABI changes, recompilation and reinstallation of third-party kernel modules may be necessary. Follow vendor instructions for updating to the specified package versions to fully remediate the issue.
Description
A vulnerability in the Linux kernel io_uring subsystem (CVE-2026-46315) was resolved by ensuring that waitid info is cleared before copying it to userspace. The flaw involved stale data exposure due to uninitialized memory being copied when a wait operation completed without reporting a child event. This issue has been addressed in updated Linux kernel packages. The vulnerability has a medium severity rating with a CVSS score of 5.5 and does not impact confidentiality or integrity but can cause availability issues. A patch is available and should be applied to affected systems.
References
- ubuntu.com/security/CVE-2026-46315 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-46315 (opens in a new tab)
- git.kernel.org/linus/93d93f5f8da791e98159795c6ef683f45bd95d13 (opens in a new tab)
- git.kernel.org/stable/c/4d2a0de611ab60d02fc768ae0cd5918b16bd5474 (opens in a new tab)
- git.kernel.org/stable/c/93d93f5f8da791e98159795c6ef683f45bd95d13 (opens in a new tab)
- git.kernel.org/stable/c/954518e5a4a5efc5033253f6e36fc7b9f98363a3 (opens in a new tab)
- git.kernel.org/stable/c/b737c6612c60c23b40a9f31749b99e6f61943847 (opens in a new tab)
- ubuntu.com/security/notices/USN-8566-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8568-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8569-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8603-1 (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-8729-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8761-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8729-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8761-2 (opens in a new tab)