CVE-2023-54276: nfsd: move init of percpu reply_cache_stats counters back to nfsd_init_net
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: 0.19% (FIRST EPSS).
- Fixed version: Linux Linux 3025d489f9c8984d1bf5916c4a20097ed80fca5c, 66a178177b2b3bb1d71e854c5e7bbb320eb0e566, 768c408594b52d8531e1a8ab62e5620c19213e73.
Low priority for now. Upgrade to Linux Linux 3025d489f9c8984d1bf5916c4a20097ed80fca5c, 66a178177b2b3bb1d71e854c5e7bbb320eb0e566, 768c408594b52d8531e1a8ab62e5620c19213e73 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: nfsd: move init of percpu reply_cache_stats counters back to nfsd_init_net Commit f5f9d4a314da ("nfsd: move reply cache initialization into nfsd startup") moved the initialization of the reply cache into nfsd startup, but didn't account for the stats counters, which can be accessed before nfsd is ever started. The result can be a NULL pointer dereference when someone accesses /proc/fs/nfsd/reply_cache_stats while nfsd is still shut down. This is a regression and a user-triggerable oops in the right situation: - non-x86_64 arch - /proc/fs/nfsd is mounted in the namespace - nfsd is not started in the namespace - unprivileged user calls "cat /proc/fs/nfsd/reply_cache_stats" Although this is easy to trigger on some arches (like aarch64), on x86_64, calling this_cpu_ptr(NULL) evidently returns a pointer to the fixed_percpu_data. That struct looks just enough like a newly initialized percpu var to allow nfsd_reply_cache_stats_show to access it without Oopsing. Move the initialization of the per-net+per-cpu reply-cache counters back into nfsd_init_net, while leaving the rest of the reply cache allocations to be done at nfsd startup time. Kudos to Eirik who did most of the legwork to track this down.
- Published
- Dec 30, 2025
- Updated
- Jun 17, 2026
- EPSS
- 0.1% · 9th 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
- 6.3affected
- 4e18b58b106e34ac69d3052dd91f520bd83cf2fc and later · before 3025d489f9c8984d1bf5916c4a20097ed80fca5caffected · git
- 70fdee548c036c6bdb496f284c9e78f1654b6dd0 and later · before 8549384d0f65981761fe2077d04fa2a8d37b54e0affected · git
- e7e571ed4ec7bb50136233d8e7b986efef2af8c1 and later · before 66a178177b2b3bb1d71e854c5e7bbb320eb0e566affected · git
- f5f9d4a314da88c0a5faa6d168bf69081b7a25ae and later · before 768c408594b52d8531e1a8ab62e5620c19213e73affected · git
- f5f9d4a314da88c0a5faa6d168bf69081b7a25ae and later · before ed9ab7346e908496816cffdecd46932035f66e2eaffected · git
- before 6.3not affected · semver
- 6.4.4 and later · up to and including 6.4.*not affected · semver
- 6.5 and laternot affected · original_commit_for_fix
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:13 | linux | before 6.4.4-1 | 6.4.4-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
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- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
Published before and after this one in the same product
- ← EarlierCVE-2023-54274Dec 30, 2025 · RDMA/srpt: Add a check for valid 'mad_agent' pointer0Monitor
- ← EarlierCVE-2023-54275Dec 30, 2025 · wifi: ath11k: Fix memory leak in ath11k_peer_rx_frag_setup0Monitor
- Later →CVE-2023-54277Dec 30, 2025 · fbdev: udlfb: Fix endpoint check0Monitor
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 | 3025d489f9c8984d1bf5916c4a20097ed80fca5c | Vendor (CNA) |
| Linux Linux | 66a178177b2b3bb1d71e854c5e7bbb320eb0e566 | Vendor (CNA) |
| Linux Linux | 768c408594b52d8531e1a8ab62e5620c19213e73 | Vendor (CNA) |
| Linux Linux | 8549384d0f65981761fe2077d04fa2a8d37b54e0 | Vendor (CNA) |
| Linux Linux | ed9ab7346e908496816cffdecd46932035f66e2e | Vendor (CNA) |
| debian:linux | 6.4.4-1 · Debian:13 | 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.
No history yet (it accumulates with the daily EPSS job).
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)
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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✗ → ✓
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References
Show all references (4 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.