CVE-2026-90067Public exploitNetwork attack vector

Kernel warning via undersized Ceph banner payload

Published Sep 17, 2026 · Updated Sep 18, 2026

Improper banner-length validation in affected Linux branches beginning with 5.11 allows context-dependent attackers to trigger a kernel warning. process_banner_prefix() accepts a payload_len below the required 16 bytes and prepares a zero-length socket read, violating the receive-state invariant in populate_in_iter(). The path requires a kernel Ceph client connection to a malicious msgr2 peer; public testing reproduces the warning but does not classify it as denial of service.

CVSS severity5.3
Medium
EPSS probability0.67%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper banner-length validation in affected Linux branches beginning with 5.11 allows context-dependent attackers to trigger a kernel warning. process_banner_prefix() accepts a payload_len below the required 16 bytes and prepares a zero-length socket read, violating the receive-state invariant in populate_in_iter(). The path requires a kernel Ceph client connection to a malicious msgr2 peer; public testing reproduces the warning but does not classify it as denial of service.

The record

CVE
CVE-2026-90067
Published
Sep 17, 2026
Updated
Sep 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 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=5.11
  2. Affected versionversion=cd1a677cad994021b19665ed476aea63f5d54f31 <279c0852999fd2384f4a88155091a99e81f96873
  3. Affected versionversion=cd1a677cad994021b19665ed476aea63f5d54f31 <3b2e62a7655d347a845a91155610ddae11daffc6
  4. Affected versionversion=cd1a677cad994021b19665ed476aea63f5d54f31 <6cf666e47f2b51d5a887ec8a3226cde951757d27
  5. Affected versionversion=cd1a677cad994021b19665ed476aea63f5d54f31 <6d1c6f228854aa89844fd0152d7ed7ac72a55e89
  6. Affected versionversion=cd1a677cad994021b19665ed476aea63f5d54f31 <c1b937ff24b19e69aa7fb1b0f46a74d4c9668692
  7. Affected versionversion=cd1a677cad994021b19665ed476aea63f5d54f31 <c77633a9595658210a6e216a071e5a396a0835a7
  8. Affected versionversion=cd1a677cad994021b19665ed476aea63f5d54f31 <f374967fcdf04001c9b66df1c19106fa83cd91f7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.11; version=cd1a677cad994021b19665ed476aea63f5d54f31 <279c0852999fd2384f4a88155091a99e81f96873; version=cd1a677cad994021b19665ed476aea63f5d54f31 <3b2e62a7655d347a845a91155610ddae11daffc6; version=cd1a677cad994021b19665ed476aea63f5d54f31 <6cf666e47f2b51d5a887ec8a3226cde951757d27; version=cd1a677cad994021b19665ed476aea63f5d54f31 <6d1c6f228854aa89844fd0152d7ed7ac72a55e89; version=cd1a677cad994021b19665ed476aea63f5d54f31 <c1b937ff24b19e69aa7fb1b0f46a74d4c9668692; version=cd1a677cad994021b19665ed476aea63f5d54f31 <c77633a9595658210a6e216a071e5a396a0835a7; version=cd1a677cad994021b19665ed476aea63f5d54f31 <f374967fcdf04001c9b66df1c19106fa83cd91f7

Published CVSS scores

5.3Amazon LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

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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