CVE-2026-80893: mm/hugetlb: fix swap entry corruption when clearing uffd-wp at fork()
Noroxi assessment
Priority: Monitor (action score 0/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.17% (FIRST EPSS).
- Fixed version: Linux Linux 2b9a07002c2f296aa6a9c591213933d3492e3089, 2fa11c60c9c06bafc19cf4d9efdaa36a38079e87, 69cb5825d9988c7944bc9f1dc08cb233655405a7; azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 6.6.152.1-1.
Low priority for now. Upgrade to Linux Linux 2b9a07002c2f296aa6a9c591213933d3492e3089, 2fa11c60c9c06bafc19cf4d9efdaa36a38079e87, 69cb5825d9988c7944bc9f1dc08cb233655405a7; azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 6.6.152.1-1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: fix swap entry corruption when clearing uffd-wp at fork() copy_hugetlb_page_range() clears the uffd-wp bit of migration and hwpoison entries with huge_pte_clear_uffd_wp(), which operates on the present-PTE bit position. Swap entries keep the uffd-wp state elsewhere -- the migration branch reads and sets it with pte_swp_uffd_wp() and pte_swp_mkuffd_wp() -- and the present-PTE position falls into the swap payload. On x86-64 it lands in the inverted swap offset, where a naturally-aligned hugetlb PFN always has the affected bit set, so the clear advances the encoded PFN by two pages. No userfaultfd needs to be involved: the clear is guarded only by the child VMA not being uffd-wp registered, so a plain fork() with an in-flight hugetlb migration entry (or a poisoned hugetlb page) corrupts the entry copied into the child. Instrumenting the clear and forking after MADV_HWPOISON on a 2MB anon hugetlb page shows: offset before=120e00 offset after =120e02 The fallout is mostly latent: rmap walks match migration entries by folio range and remove_migration_pte() rebuilds the PTE from the folio, so a within-folio PFN skew heals once migration completes. But any path that re-encodes the corrupted offset -- e.g. hugetlb_change_protection() rewriting a writable migration entry via make_readable_migration_entry(swp_offset(entry)) -- propagates it. Migration entries legitimately carry uffd-wp, so clear it with pte_swp_clear_uffd_wp(), matching copy_nonpresent_pte() and move_huge_pte(). A hwpoison entry, on the other hand, never carries the uffd-wp bit: it is installed fresh by make_hwpoison_entry() (try_to_unmap_one() does not preserve uffd-wp on the hwpoison path) and hugetlb_change_protection() leaves hwpoison entries untouched. There was nothing to clear there, only the corruption, so drop the clear entirely.
- Published
- Sep 4, 2026
- Updated
- Sep 4, 2026
- EPSS
- 0.1% · 6th percentile
- CWE
- —
Report tools
Action score
0
Monitor
Low priority for now.
- CVSS
- 0 / 40 · —
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
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Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 5.19affected
- bc70fbf269fdff410b0b6d75c3770b9f59117b90 and later · before f1b1311c0352873137768bac5a126e491271a747affected · git
- bc70fbf269fdff410b0b6d75c3770b9f59117b90 and later · before 69cb5825d9988c7944bc9f1dc08cb233655405a7affected · git
- bc70fbf269fdff410b0b6d75c3770b9f59117b90 and later · before 8b0de7005b148738d79d6c45594d566489948a68affected · git
- bc70fbf269fdff410b0b6d75c3770b9f59117b90 and later · before 2b9a07002c2f296aa6a9c591213933d3492e3089affected · git
- bc70fbf269fdff410b0b6d75c3770b9f59117b90 and later · before 2fa11c60c9c06bafc19cf4d9efdaa36a38079e87affected · git
- bc70fbf269fdff410b0b6d75c3770b9f59117b90 and later · before 83abe2fd5b3aeb3123b5408a5a91709c5538fb23affected · git
- before 5.19not affected · semver
- 6.1.183 and later · up to and including 6.1.*not affected · semver
- 6.6.151 and later · up to and including 6.6.*not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.1.187-1 | 6.1.187-1 |
| Debian:12 | linux-6.12 | before 6.12.107-1~deb12u1 | 6.12.107-1~deb12u1 |
| Debian:13 | linux | before 6.12.105-1 | 6.12.105-1 |
| Debian:14 | linux | before 7.1.8-1 | 7.1.8-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
Published before and after this one in the same product
- ← EarlierCVE-2026-80891Sep 4, 2026 · KVM: s390: pci: Validate AIBV and AISB before pinning guest pages0Monitor
- ← EarlierCVE-2026-80892Sep 4, 2026 · erofs: cap LZMA stream pool size0Monitor
- Later →CVE-2026-80894Sep 4, 2026 · iommufd: Fix wrong hwpt passed to iommufd_auto_response_faults on replace0Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 2b9a07002c2f296aa6a9c591213933d3492e3089 | Vendor (CNA) |
| Linux Linux | 2fa11c60c9c06bafc19cf4d9efdaa36a38079e87 | Vendor (CNA) |
| Linux Linux | 69cb5825d9988c7944bc9f1dc08cb233655405a7 | Vendor (CNA) |
| Linux Linux | 83abe2fd5b3aeb3123b5408a5a91709c5538fb23 | Vendor (CNA) |
| Linux Linux | 8b0de7005b148738d79d6c45594d566489948a68 | Vendor (CNA) |
| Linux Linux | f1b1311c0352873137768bac5a126e491271a747 | Vendor (CNA) |
| azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 | 6.6.152.1-1 · Release Notes | Microsoft (MSRC) |
| debian:linux | 6.1.187-1 · Debian:12 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.107-1~deb12u1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
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Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
No CVSS vector for this record, so attack conditions can't be derived.
Weakness class (CWE)
—
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (5 more)Show less
- git.kernel.org/stable/c/2fa11c60c9c06bafc19cf4d9efdaa36a38079e87
- git.kernel.org/stable/c/69cb5825d9988c7944bc9f1dc08cb233655405a7
- git.kernel.org/stable/c/83abe2fd5b3aeb3123b5408a5a91709c5538fb23
- git.kernel.org/stable/c/8b0de7005b148738d79d6c45594d566489948a68
- git.kernel.org/stable/c/f1b1311c0352873137768bac5a126e491271a747
Vendor advisories and official records. Exploit/PoC links are deliberately left out.