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NVD / CVE Program· CNA Linux

CVE-2026-89549: sunrpc: route to a populated pool in svc_pool_for_cpu()

Noroxi assessment

Priority: Monitor (action score 30/100)

  • 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: 0.70% (FIRST EPSS); higher than 53.6% 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.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Linux Linux 011479cf9a7657d4a3e7cc42a784ac63df594170, 6f66d38e2a6c78d48723ea17ad86135ec80ca24b, 8f766d2d0b4dabf54f8b35812df2b4f481d13316.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 011479cf9a7657d4a3e7cc42a784ac63df594170, 6f66d38e2a6c78d48723ea17ad86135ec80ca24b, 8f766d2d0b4dabf54f8b35812df2b4f481d13316 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: sunrpc: route to a populated pool in svc_pool_for_cpu() svc_set_num_threads() spreads the requested threads evenly across the service's pools (base = nrservs / sv_nrpools). When a service runs fewer threads than it has pools -- e.g. an nfsd configured with fewer threads than the host has NUMA nodes while running in "pernode" or "percpu" mode -- the trailing pools are left with no threads at all. svc_xprt_enqueue() selects a pool from the CPU servicing the transport, queues the transport on that pool's sp_xprts, and only wakes a thread from the same pool. Each thread services exclusively its own pool, so a transport that lands on a threadless pool is enqueued on sp_xprts and never picked up: the connection hangs indefinitely. Have svc_pool_for_cpu() skip pools that currently have no threads, falling back to the next populated pool. This trades NUMA locality for a guarantee that the work is actually serviced. sp_nrthreads is only updated under the service mutex; the lockless read here is a best-effort routing hint, so annotate it with data_race().

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Sep 11, 2026
Updated
Oct 19, 2026
EPSS
0.7% · 53th percentile
CWE
—

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.5
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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When you'll hear from us

  • when it enters CISA KEV
  • 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

    • 2.6.19affected
    • bfd241600a3b0db4fe43c859f1460d0a958d924a and later · before 9accc25e5af0bac8479f6054e674b2c593c45281affected · git
    • bfd241600a3b0db4fe43c859f1460d0a958d924a and later · before 6f66d38e2a6c78d48723ea17ad86135ec80ca24baffected · git
    • bfd241600a3b0db4fe43c859f1460d0a958d924a and later · before d79d7b9e8acbb53e2d60f6b24afc13e2f15e691faffected · git
    • bfd241600a3b0db4fe43c859f1460d0a958d924a and later · before edb20e8c03aebacb409968c99d046f509c6c485aaffected · git
    • bfd241600a3b0db4fe43c859f1460d0a958d924a and later · before 011479cf9a7657d4a3e7cc42a784ac63df594170affected · git
    • bfd241600a3b0db4fe43c859f1460d0a958d924a and later · before 9d04d64ad192439835ed9884d767353061c3ed6faffected · git
    • bfd241600a3b0db4fe43c859f1460d0a958d924a and later · before 8f766d2d0b4dabf54f8b35812df2b4f481d13316affected · git
    • bfd241600a3b0db4fe43c859f1460d0a958d924a and later · before f6310491c4cdb88af73aa551ec9df1f10a90c709affected · git
    • before 2.6.19not 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-2026-89547Sep 11, 2026 · SUNRPC: Check svc pool percpu counter allocation
    32Monitor
  • ← EarlierCVE-2026-89548Sep 11, 2026 · SUNRPC: always drain cache_cleaner before destroying a cache_detail
    31Monitor
  • Later →CVE-2026-89550Sep 11, 2026 · SUNRPC: svcauth_gss: enforce krb5 token minimum length
    39Monitor

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 Linux011479cf9a7657d4a3e7cc42a784ac63df594170Vendor (CNA)
Linux Linux6f66d38e2a6c78d48723ea17ad86135ec80ca24bVendor (CNA)
Linux Linux8f766d2d0b4dabf54f8b35812df2b4f481d13316Vendor (CNA)
Linux Linux9accc25e5af0bac8479f6054e674b2c593c45281Vendor (CNA)
Linux Linux9d04d64ad192439835ed9884d767353061c3ed6fVendor (CNA)
Linux Linuxd79d7b9e8acbb53e2d60f6b24afc13e2f15e691fVendor (CNA)
Linux Linuxedb20e8c03aebacb409968c99d046f509c6c485aVendor (CNA)
Linux Linuxf6310491c4cdb88af73aa551ec9df1f10a90c709Vendor (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).

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 researchers

Finders, 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.

All national notices →

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
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

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

All records