CVE-2026-98261

Kernel use-after-free via premature channel release

Published Oct 6, 2026 · Updated Oct 6, 2026

A use-after-free in the Linux kernel CIFS client allows context-dependent attackers to trigger access to freed server state during SMB multichannel reconnect. The cifs_chan_skip_or_disable() function drops a secondary channel’s last reference before signaling that channel and reading its primary_server pointer. The path requires an active CIFS connection whose server stops supporting a secondary channel; the public patch does not establish reliable crash or code-execution impact.

CVSS severityUnavailable
Unscored
EPSS probability0.44%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A use-after-free in the Linux kernel CIFS client allows context-dependent attackers to trigger access to freed server state during SMB multichannel reconnect. The cifs_chan_skip_or_disable() function drops a secondary channel’s last reference before signaling that channel and reading its primary_server pointer. The path requires an active CIFS connection whose server stops supporting a secondary channel; the public patch does not establish reliable crash or code-execution impact.

The record

CVE
CVE-2026-98261
Published
Oct 6, 2026
Updated
Oct 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 6, 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=50e8363ecc85da49764781da90ebffe1a657b370 <0338489960ddad6368bce55e8adbc176c523093d
  2. Affected versionversion=6.6.15 <6.6.158
  3. Affected versionversion=6.7.3 <6.8
  4. Affected versionversion=6.8
  5. Affected versionversion=d61ba1d71ea6039eca7ada870bf3f0c3c8fc12e4
  6. Affected versionversion=f591062bdbf4742b7f1622173017f19e927057b0 <717e0a25036b6c92cecace30913b2d874a4c22b8
  7. Affected versionversion=f591062bdbf4742b7f1622173017f19e927057b0 <7a1b27780b113583a94256d58dabfe7c0d9286e7
  8. Affected versionversion=f591062bdbf4742b7f1622173017f19e927057b0 <edd52eae5fcfb8433b6bb0e7cd98db438fe01227
  9. Affected versionversion=f591062bdbf4742b7f1622173017f19e927057b0 <fcc0a935bb6e37ecbf7e4335061309f896f35780

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=50e8363ecc85da49764781da90ebffe1a657b370 <0338489960ddad6368bce55e8adbc176c523093d; version=6.6.15 <6.6.158; version=6.7.3 <6.8; version=6.8; version=d61ba1d71ea6039eca7ada870bf3f0c3c8fc12e4; version=f591062bdbf4742b7f1622173017f19e927057b0 <717e0a25036b6c92cecace30913b2d874a4c22b8; version=f591062bdbf4742b7f1622173017f19e927057b0 <7a1b27780b113583a94256d58dabfe7c0d9286e7; version=f591062bdbf4742b7f1622173017f19e927057b0 <edd52eae5fcfb8433b6bb0e7cd98db438fe01227; version=f591062bdbf4742b7f1622173017f19e927057b0 <fcc0a935bb6e37ecbf7e4335061309f896f35780

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.

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)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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