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NVD / CVE Program· CNA Linux

CVE-2026-90151: NFSv4: remove callback IDR entry on client allocation failure

CriticalCVSS 9.8 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 39/100)

  • 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: 0.74% (FIRST EPSS); higher than 55.4% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 3f2387e8bfbc4efda5d77c3a11a028d0a119c48f, 5891c03e150920618db0e9c4ea2d772abacdcfd1, 68c721391b761dbe38d5b0094d2bb6e8489ad92b.

Low priority for now. Upgrade to Linux Linux 3f2387e8bfbc4efda5d77c3a11a028d0a119c48f, 5891c03e150920618db0e9c4ea2d772abacdcfd1, 68c721391b761dbe38d5b0094d2bb6e8489ad92b 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: NFSv4: remove callback IDR entry on client allocation failure nfs4_alloc_client() allocates an NFSv4.0 callback identifier before it finishes setting up the client. If any later initialization step fails, the error path frees the nfs_client directly with nfs_free_client(). That bypasses nfs_put_client(), which is where the callback IDR entry is removed during normal teardown. A failed allocation can therefore leave cb_ident_idr pointing at a freed nfs_client. A later NFSv4.0 callback lookup by cb_ident would find the stale pointer and take a reference to it. Make the callback IDR removal helper callable by the allocation failure path, and remove the callback identifier before freeing the client. This was found by a local static-analysis checker for publish-before-free lifetime bugs and confirmed by manual inspection.

Published
Sep 17, 2026
Updated
Oct 19, 2026
EPSS
0.7% · 55th percentile
CWE
—

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CNA vs NVD score

NVD
—
CNA · Linux
9.8
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.

Follow CVE-2026-90151

When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

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Affected 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

    • 2.6.38affected
    • f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and later · before 68c721391b761dbe38d5b0094d2bb6e8489ad92baffected · git
    • f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and later · before 9bfdd0f591307b5198826a0e7a5b2f35f87acd2daffected · git
    • f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and later · before 7c4812eb96bdcafb31a65b12f2aa96659429d1d4affected · git
    • f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and later · before fc95ca82d5ae598c428ab5a00ae69f8526d59371affected · git
    • f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and later · before 80b1c3d5a881f7d9081aa9f46da9742878a0f893affected · git
    • f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and later · before 3f2387e8bfbc4efda5d77c3a11a028d0a119c48faffected · git
    • f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and later · before 5891c03e150920618db0e9c4ea2d772abacdcfd1affected · git
    • f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and later · before d05c2007b3d84ccba11dc6e9cb3202768cc72f14affected · git
    • before 2.6.38not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-90149Sep 17, 2026 · NFSv4/flexfiles: fix NULL dereference for NFSv4.0 data servers
    30Monitor
  • ← EarlierCVE-2026-90150Sep 17, 2026 · pnfs/blocklayout: Fix device leaks on parse failure
    0Monitor
  • Later →CVE-2026-90152Sep 17, 2026 · smb/server: fix session leak in ksmbd_session_register()
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux3f2387e8bfbc4efda5d77c3a11a028d0a119c48fVendor (CNA)
Linux Linux5891c03e150920618db0e9c4ea2d772abacdcfd1Vendor (CNA)
Linux Linux68c721391b761dbe38d5b0094d2bb6e8489ad92bVendor (CNA)
Linux Linux7c4812eb96bdcafb31a65b12f2aa96659429d1d4Vendor (CNA)
Linux Linux80b1c3d5a881f7d9081aa9f46da9742878a0f893Vendor (CNA)
Linux Linux9bfdd0f591307b5198826a0e7a5b2f35f87acd2dVendor (CNA)
Linux Linuxd05c2007b3d84ccba11dc6e9cb3202768cc72f14Vendor (CNA)
Linux Linuxfc95ca82d5ae598c428ab5a00ae69f8526d59371Vendor (CNA)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package 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.

EPSS, last 120 days+1% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • 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
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/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.

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records