Linux kernel hugetlb mremap advances destination address too far
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 5 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
Linux kernel versions from 6.0 are affected in the hugetlb code used by mremap(). move_hugetlb_page_tables() advances the destination address too far when it skips page tables, which can cause follow-up errors. A reproducer triggered a kernel panic on x86-64 before the fix.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: preserve mremap address delta when skipping page tables move_hugetlb_page_tables() optimizes mremap() by advancing to the last entry in the page table when the source page table does not exist, either initially or after unsharing a PMD table. The common loop increment then steps to the first entry in the next page table. However, the code advances both the source and destination addresses to the last entries in their respective page tables, which is wrong. The destination address must be advanced only by the same amount as the source address. If the source and destination offsets within their page tables differ, the destination address can be advanced too far, causing follow-up issues. Fix this by advancing the destination address by the source advance distance. With a reproducer, we were able to trigger a kernel panic on x86-64. With this fix in place, we can no longer reproduce the issue.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Upgrade the Linux kernel to 6.1.191, 6.6.160, 6.12.112, 6.18.55, 7.2.9 or 7.3. Red Hat Enterprise Linux 9 and 10 and OpenShift Container Platform 4 and 5 have no fix available, and Red Hat Enterprise Linux 6 has no fix planned.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
- Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.160, 6.12.112, 6.18.55, 7.2.9, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet |
Not affected: 4 products
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-07 Threatist record created from CVE-2026-98373
- 2026-10-07 Alias added: GHSA-7phr-r52q-xg92
- 2026-10-10 Affected versions changed · Red Hat
- 2026-10-10 CVSS score added · Red Hat
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-21 Fix available: Linux/[email protected], Linux/Linux@cf73ef2a761df9329af116c905a7a94b317921e4 · CNA
- 2026-10-21 1 new reference · CNA
- 2026-10-30 Affected versions changed · Red Hat
- 2026-10-30 Fix available: Linux/[email protected], Linux/Linux@ab4f0f68cf4773dc0513baccbbe790c80a301773 · CNA
- 2026-10-30 1 new reference · CNA
- 2026-11-03 CVSS score changed · Red Hat
References
Other 6
- https://git.kernel.org/stable/c/ab4f0f68cf4773dc0513baccbbe790c80a301773
- https://git.kernel.org/stable/c/cf73ef2a761df9329af116c905a7a94b317921e4
- https://git.kernel.org/stable/c/7a96b0f657c8d799ea5b8e02fc9ec7cca0e6e7ff
- https://git.kernel.org/stable/c/850cc4a84b36a0062dcd0391acd2450e20ab0767
- https://git.kernel.org/stable/c/480a39b0a12c977ed6e755f3d12a23424c57d11f
- https://git.kernel.org/stable/c/9bdad082d44bdcf93716973dcba6be77e8a06e7b
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Sources
- CVE-2026-98373 · CVE Program
- CVE-2026-98373 · NVD
- FIRST EPSS
- GHSA-7phr-r52q-xg92 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98373 · Red Hat security data · CC BY 4.0
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