CVE-2026-89648Network attack vector

Client denial of service via unbounded inode intervals

Published Sep 11, 2026 · Updated Sep 11, 2026

Denial of service in the CephFS client in Linux 5.7 allows malicious or compromised MDS servers to exhaust client CPU and memory. ceph_parse_deleg_inos() trusts each decoded 64-bit interval length, loops over that value, and accumulates entries in the session xarray without per-reply or per-session bounds. Exploitation requires control of an MDS serving the client and can make that client spin or consume memory without limit.

CVSS severityUnavailable
Unscored
EPSS probability0.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the CephFS client in Linux 5.7 allows malicious or compromised MDS servers to exhaust client CPU and memory. ceph_parse_deleg_inos() trusts each decoded 64-bit interval length, loops over that value, and accumulates entries in the session xarray without per-reply or per-session bounds. Exploitation requires control of an MDS serving the client and can make that client spin or consume memory without limit.

The record

CVE
CVE-2026-89648
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=5.7
  2. Affected versionversion=d4846487870897a5a149a3220c95bfd5728f9247 <4bd3158bd62466d57ed72a3f7bc5f205fedd6919
  3. Affected versionversion=d4846487870897a5a149a3220c95bfd5728f9247 <c040e139f1a629b767f900bbbc3f9892c290ed85
  4. Affected versionversion=d4846487870897a5a149a3220c95bfd5728f9247 <f341270ac5f5077804d7837ce77b0f0df1cea29d

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.7; version=d4846487870897a5a149a3220c95bfd5728f9247 <4bd3158bd62466d57ed72a3f7bc5f205fedd6919; version=d4846487870897a5a149a3220c95bfd5728f9247 <c040e139f1a629b767f900bbbc3f9892c290ed85; version=d4846487870897a5a149a3220c95bfd5728f9247 <f341270ac5f5077804d7837ce77b0f0df1cea29d

Published CVSS scores

No CVSS assessment is available in this record.

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.

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

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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