CVE-2026-97945: Linux kernel · x86/mm: Fix user-space data loss with MADV_FREE and THP
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 14:05 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 25 Sep 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?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 fix for this vulnerability is available in the Linux kernel. Users should update to a patched kernel version that includes the corrected pmd_modify() behavior preserving the hardware dirty bit. Since this is a kernel-level issue, applying the official kernel update is the recommended remediation. There is no indication that temporary workarounds or configuration changes can fully mitigate the issue.
Description
A vulnerability in the Linux kernel's x86 memory management subsystem causes user-space data loss when using MADV_FREE with Transparent Huge Pages (THP). The issue arises because the pmd_modify() function incorrectly clears the hardware dirty bit, leading to data being discarded under memory reclaim pressure despite being rewritten. This affects both anonymous and file-backed PMD-mapped THPs. The bug has been fixed by adjusting pmd_modify() to preserve the dirty bit similarly to related functions.
References
- ubuntu.com/security/CVE-2026-97945 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-97945 (opens in a new tab)
- git.kernel.org/stable/c/55ddbc2ca6d5db64d44c3fb8f8705b4d39eb30b7 (opens in a new tab)
- git.kernel.org/stable/c/a5ad97cbcfcec31430268441c10eedde73200177 (opens in a new tab)
- git.kernel.org/stable/c/f7491d7c81db0e7c304a7bd757a76d2fbeaff80e (opens in a new tab)
- git.kernel.org/stable/c/e4d569fe2f436a9b58c048fefabf56eab68c1b7e (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-97945 (opens in a new tab)
- git.kernel.org/stable/c/b5dec6dfb593d81fec15ba43c4fe5d58f10a49a2 (opens in a new tab)