CVE-2026-64269Network attack vector

Host-memory disclosure via oversized RTRS descriptor

Published Jul 25, 2026 · Updated Jul 25, 2026

Out-of-bounds read in Linux Kernel RTRS servers allows remote attackers to read host memory via a crafted READ request. In rdma_write_sg(), the peer-controlled desc[0].len sets an RDMA write length without comparison to max_chunk_size, reading beyond the fixed chunk. Disclosure requires no IOMMU or passthrough mode; a translating IOMMU faults the access and aborts the connection.

CVSS severity9.1
Critical
EPSS probability0.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Linux Kernel RTRS servers allows remote attackers to read host memory via a crafted READ request. In rdma_write_sg(), the peer-controlled desc[0].len sets an RDMA write length without comparison to max_chunk_size, reading beyond the fixed chunk. Disclosure requires no IOMMU or passthrough mode; a translating IOMMU faults the access and aborts the connection.

The record

CVE
CVE-2026-64269
Published
Jul 25, 2026
Updated
Jul 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.8
  2. Affected versionversion=9cb837480424e78ed585376f944088246685aec3 <2912f3d40355dabc08fdbaaf2764d02445fe88dc
  3. Affected versionversion=9cb837480424e78ed585376f944088246685aec3 <5a45d0aa1fa50a333ce5763ade744e2d89838667
  4. Affected versionversion=9cb837480424e78ed585376f944088246685aec3 <68c09762172f6224e9ddf9b0a60bacbb36e443eb
  5. Affected versionversion=9cb837480424e78ed585376f944088246685aec3 <6cada540150894e81042a0ae0c796a21a9a877da
  6. Affected versionversion=9cb837480424e78ed585376f944088246685aec3 <6f40246f4312fdbab5a13cc440adebf95eb2aa66
  7. Affected versionversion=9cb837480424e78ed585376f944088246685aec3 <963af8d97a8c6a117134a8d0db1415e0489200b1
  8. Affected versionversion=9cb837480424e78ed585376f944088246685aec3 <da3e44add94b05dfde56f898421922f5cf35705f

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.8; version=9cb837480424e78ed585376f944088246685aec3 <2912f3d40355dabc08fdbaaf2764d02445fe88dc; version=9cb837480424e78ed585376f944088246685aec3 <5a45d0aa1fa50a333ce5763ade744e2d89838667; version=9cb837480424e78ed585376f944088246685aec3 <68c09762172f6224e9ddf9b0a60bacbb36e443eb; version=9cb837480424e78ed585376f944088246685aec3 <6cada540150894e81042a0ae0c796a21a9a877da; version=9cb837480424e78ed585376f944088246685aec3 <6f40246f4312fdbab5a13cc440adebf95eb2aa66; version=9cb837480424e78ed585376f944088246685aec3 <963af8d97a8c6a117134a8d0db1415e0489200b1; version=9cb837480424e78ed585376f944088246685aec3 <da3e44add94b05dfde56f898421922f5cf35705f

Published CVSS scores

9.1kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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