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NVD / CVE Program· CNA Linux

CVE-2026-89526: svcrdma: Validate Read chunk positions before reconstruction

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: 0.68% (FIRST EPSS); higher than 52.4% 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.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Linux Linux 3779b7b9e7d1c8ba4738f9d327de3b0288cefe9b, 3861eeabaebe243050952b34063763527c44e1fe, 577097455d084610fc31e91e6a61c5793b6f04ba; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 Release Notes.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 3779b7b9e7d1c8ba4738f9d327de3b0288cefe9b, 3861eeabaebe243050952b34063763527c44e1fe, 577097455d084610fc31e91e6a61c5793b6f04ba; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 Release Notes 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: svcrdma: Validate Read chunk positions before reconstruction The RPC/RDMA Read chunk position field is supplied by the remote client and stored verbatim in the parsed chunk list. xdr_count_read_segments() checks only 4-byte alignment; it never compares the position against the received inline body length. In the single-chunk path, svc_rdma_read_complete_one() splits the head and tail kvecs at ch_position. A position past the inline body underflows the tail length, exposing adjacent slab memory to the upper XDR decoder. In the multi-chunk path, svc_rdma_read_multiple_chunks() computes gap lengths between chunks as unsigned subtractions from ch_position. Overlapping Read chunks cause these subtractions to underflow. A final position past the inline body likewise underflows the trailing gap length. svc_rdma_copy_inline_range() then copies past the receive buffer into request pages that are returned to the client through the Reply channel. Bound inline-range copies in svc_rdma_copy_inline_range() against the decoded inline RPC body saved in rc_saved_arg. Reject a single Read chunk positioned beyond that body, and reject multi-chunk lists where accumulated read bytes exceed the next chunk's position. Apply the same position and overlap checks in the call-chunk interleaving path.

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Sep 11, 2026
Updated
Oct 30, 2026
EPSS
0.6% · 52th 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 · 0.6%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

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.

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When you'll hear from us

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  • when exploit code appears or is weaponized
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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

    • 5.11affected
    • d96962e6d0e281bab6a48e83b42f5dce6eb28bf4 and later · before 6388f2ed36c10f59d926735b92c2b152d2c635e5affected · git
    • d96962e6d0e281bab6a48e83b42f5dce6eb28bf4 and later · before 3861eeabaebe243050952b34063763527c44e1feaffected · git
    • d96962e6d0e281bab6a48e83b42f5dce6eb28bf4 and later · before 5ab3f6d882fe07ae5e61d0bcfeea00b9409155c2affected · git
    • d96962e6d0e281bab6a48e83b42f5dce6eb28bf4 and later · before f84ec84d8d4bc65f9ae23372570349687f66fa39affected · git
    • d96962e6d0e281bab6a48e83b42f5dce6eb28bf4 and later · before 577097455d084610fc31e91e6a61c5793b6f04baaffected · git
    • d96962e6d0e281bab6a48e83b42f5dce6eb28bf4 and later · before 3779b7b9e7d1c8ba4738f9d327de3b0288cefe9baffected · git
    • before 5.11not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.6.160 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.

EcosystemPackageAffected rangeFix
AlmaLinux:10kernelbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2

+96

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-2026-89524Sep 11, 2026 · wifi: ath6kl: clamp assoc request/response lengths before subtracting IE offsets
    32Monitor
  • ← EarlierCVE-2026-89525Sep 11, 2026 · udf: reject VAT indexes equal to the entry count
    0Monitor
  • Later →CVE-2026-89527Sep 11, 2026 · svcrdma: Use svc_xprt_put to free listener on create failure
    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 Linux3779b7b9e7d1c8ba4738f9d327de3b0288cefe9bVendor (CNA)
Linux Linux3861eeabaebe243050952b34063763527c44e1feVendor (CNA)
Linux Linux577097455d084610fc31e91e6a61c5793b6f04baVendor (CNA)
Linux Linux5ab3f6d882fe07ae5e61d0bcfeea00b9409155c2Vendor (CNA)
Linux Linux6388f2ed36c10f59d926735b92c2b152d2c635e5Vendor (CNA)
Linux Linuxf84ec84d8d4bc65f9ae23372570349687f66fa39Vendor (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—Microsoft (MSRC)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.159.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
almalinux:bpftool4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-core5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-core5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-core5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel-matched5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)

+20

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

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
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.

Change log

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

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

References

Show all references (5 more)

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

All records