nvdimm/btt: reject an arena whose nfree is below the lane count
Noroxi assessment
Priority: Monitor (action score 31/100)
- 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: 0.16% (FIRST EPSS).
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: Linux Linux 59d5cd1f42b4bab3609512c3cb3d3540d3d21da7, 6a1f2e5ed9267ca19187038ac635393c165213ac, 6b1faf1f099f7060b5f1f2f0d024132581f1726e; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 59d5cd1f42b4bab3609512c3cb3d3540d3d21da7, 6a1f2e5ed9267ca19187038ac635393c165213ac, 6b1faf1f099f7060b5f1f2f0d024132581f1726e; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1 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
In the Linux kernel, the following vulnerability has been resolved: nvdimm/btt: reject an arena whose nfree is below the lane count The BTT info block's nfree field, the number of reserve free blocks, is read from the medium without validation. btt_freelist_init() and btt_rtt_init() size the per-lane freelist[] and rtt[] arrays by nfree, but the I/O path indexes them by the lane from nd_region_acquire_lane(), which is bounded by nd_region->num_lanes (ND_MAX_LANES), not by nfree. A crafted or foreign arena whose nfree is below the lane count makes freelist[lane]/rtt[lane] run past the allocation: an out-of-bounds write. btt.rst documents the nlanes = min(nfree, num_cpus) invariant, which the code does not currently honor: num_lanes is ND_MAX_LANES regardless of nfree. Reject an arena whose nfree is below num_lanes at discovery, before the per-lane arrays are allocated, enforcing that invariant.
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- EPSS
- 0.2% · 6th percentile
- CWE
- —
Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 7.8
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
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
If any of these changes, we'll tell you in the daily email digest.
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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.
—
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
- 4.2affected
- 5212e11fde4d40fa627668b4f2222d20db488f71 and later · before eb491343d2d1784121ad9af91c25b338c28913c3affected · git
- 5212e11fde4d40fa627668b4f2222d20db488f71 and later · before 59d5cd1f42b4bab3609512c3cb3d3540d3d21da7affected · git
- 5212e11fde4d40fa627668b4f2222d20db488f71 and later · before f6c5313aae794ecca8f762c1a3493de5c266f120affected · git
- 5212e11fde4d40fa627668b4f2222d20db488f71 and later · before f9bf05c63b77d000e9c01f3e47af36973887d350affected · git
- 5212e11fde4d40fa627668b4f2222d20db488f71 and later · before 6f79d1a5f2611a3d36e9312be5425cd9cb397c51affected · git
- 5212e11fde4d40fa627668b4f2222d20db488f71 and later · before 6b1faf1f099f7060b5f1f2f0d024132581f1726eaffected · git
- 5212e11fde4d40fa627668b4f2222d20db488f71 and later · before 9dfa11cef4750b67591307f2c62e47a23d60e4b7affected · git
- 5212e11fde4d40fa627668b4f2222d20db488f71 and later · before 6a1f2e5ed9267ca19187038ac635393c165213acaffected · git
- before 4.2not 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 | all versions | — |
| Debian:12 | linux-6.12 | before 6.12.111-1~deb12u1 | 6.12.111-1~deb12u1 |
| Debian:13 | linux | before 6.12.111-1 | 6.12.111-1 |
| Debian:14 | linux | before 7.2.6-1 | 7.2.6-1 |
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
- CVE-2026-74309vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler40Plan
- CVE-2026-74280crypto: marvell/octeontx - fix DMA cleanup using wrong loop index40Plan
- CVE-2026-74279crypto: cavium/cpt - fix DMA cleanup using wrong loop index40Plan
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 | 59d5cd1f42b4bab3609512c3cb3d3540d3d21da7 | Vendor (CNA) |
| Linux Linux | 6a1f2e5ed9267ca19187038ac635393c165213ac | Vendor (CNA) |
| Linux Linux | 6b1faf1f099f7060b5f1f2f0d024132581f1726e | Vendor (CNA) |
| Linux Linux | 6f79d1a5f2611a3d36e9312be5425cd9cb397c51 | Vendor (CNA) |
| Linux Linux | 9dfa11cef4750b67591307f2c62e47a23d60e4b7 | Vendor (CNA) |
| Linux Linux | eb491343d2d1784121ad9af91c25b338c28913c3 | Vendor (CNA) |
| Linux Linux | f6c5313aae794ecca8f762c1a3493de5c266f120 | Vendor (CNA) |
| Linux Linux | f9bf05c63b77d000e9c01f3e47af36973887d350 | Vendor (CNA) |
| azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 | — | Microsoft (MSRC) |
| azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 | 6.6.157.1-1 · Release Notes | Microsoft (MSRC) |
| debian:linux | 6.12.111-1 · Debian:13 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.111-1~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.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-1114 · Sep 17, 2026(Linux Kernel Güvenlik Bildirimi)
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
—
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-secondary
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 (7 more)Show less
- git.kernel.org/stable/c/6a1f2e5ed9267ca19187038ac635393c165213ac
- git.kernel.org/stable/c/6b1faf1f099f7060b5f1f2f0d024132581f1726e
- git.kernel.org/stable/c/6f79d1a5f2611a3d36e9312be5425cd9cb397c51
- git.kernel.org/stable/c/9dfa11cef4750b67591307f2c62e47a23d60e4b7
- git.kernel.org/stable/c/eb491343d2d1784121ad9af91c25b338c28913c3
- git.kernel.org/stable/c/f6c5313aae794ecca8f762c1a3493de5c266f120
- git.kernel.org/stable/c/f9bf05c63b77d000e9c01f3e47af36973887d350
Vendor advisories and official records. Exploit/PoC links are deliberately left out.