CVE-2026-46182: Linux kernel · pseries/papr-hvpipe: Prevent kernel stack memory leak to userspace
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · patch available : update Linux kernel when convenient.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available
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 28 May 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
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux@7.0.0-28.28?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws@7.0.0-1008.8?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure@7.0.0-1009.9?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde@7.0.0-1008.8?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp@7.0.0-1008.8?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke@7.0.0-1003.4?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 linux-hwe-edge kernel versions 7.0.0-28.28 or later as specified in the Ubuntu security advisory USN-8566-1. After updating, a system reboot is required. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be necessary. Follow the vendor's update instructions precisely.
Description
A vulnerability in the Linux kernel's pseries/papr-hvpipe subsystem could leak uninitialized kernel stack memory to userspace. The issue arises because the hdr struct was only partially initialized, potentially exposing reserved padding bytes containing sensitive data. This flaw has been fixed by zero-initializing the entire struct. The vulnerability affects multiple linux-hwe-edge kernel versions prior to 7.0.0-28.28 and related builds. A patch is available and should be applied to prevent potential information leakage.
References
- ubuntu.com/security/CVE-2026-46182 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-46182 (opens in a new tab)
- git.kernel.org/linus/cefeed44296261173a806bef988b26bc565da4be (opens in a new tab)
- git.kernel.org/stable/c/0479b6e9f999cc1cbad7d9f09f574fc387e605d5 (opens in a new tab)
- git.kernel.org/stable/c/cefeed44296261173a806bef988b26bc565da4be (opens in a new tab)
- git.kernel.org/stable/c/f88f8e4485b437e0a2f96a7ff1f88aa22d925659 (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)