CVE-2026-64137

Credential exposure and mount disruption via unguarded netlink

Published Jul 19, 2026 · Updated Jul 19, 2026

Improper authorization in affected Linux Kernel releases allows local users to read CIFS credentials or disrupt witness-enabled mounts. The CIFS generic-netlink family omits capability checks for SWN_NOTIFY and SWN multicast membership, allowing forged notices and receipt of registration messages. A local unprivileged user needs a witness-enabled CIFS mount; NTLM sessions expose usernames, domains, and passwords, while forged notices redirect reconnects or interrupt mounts.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authorization in affected Linux Kernel releases allows local users to read CIFS credentials or disrupt witness-enabled mounts. The CIFS generic-netlink family omits capability checks for SWN_NOTIFY and SWN multicast membership, allowing forged notices and receipt of registration messages. A local unprivileged user needs a witness-enabled CIFS mount; NTLM sessions expose usernames, domains, and passwords, while forged notices redirect reconnects or interrupt mounts.

The record

CVE
CVE-2026-64137
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1552, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 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=fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 <969bc6370334a5b4720c5470783295d6484bbc95
  3. Affected versionversion=fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 <9919021a3b7974ae66a5f9915e3a48c10cfd409b
  4. Affected versionversion=fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 <9cf7eb8919344932f909b2fac76296f7656fda8d
  5. Affected versionversion=fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 <a3238b09c58f323e40743ce174cd0ab81b5c09ed
  6. Affected versionversion=fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 <a8d17d22db591099519a89f14dd24810daba74c3
  7. Affected versionversion=fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 <c2397b93fbb6f44a788fff30f99be2c20cc5e50f
  8. Affected versionversion=fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 <d1ebfce2c1d161186a82e77590bf7da2ea1bce91

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.11; version=fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 <969bc6370334a5b4720c5470783295d6484bbc95; version=fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 <9919021a3b7974ae66a5f9915e3a48c10cfd409b; version=fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 <9cf7eb8919344932f909b2fac76296f7656fda8d; version=fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 <a3238b09c58f323e40743ce174cd0ab81b5c09ed; version=fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 <a8d17d22db591099519a89f14dd24810daba74c3; version=fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 <c2397b93fbb6f44a788fff30f99be2c20cc5e50f; version=fed979a7e082bd9f25f9002c3c4f8740dacd0bc8 <d1ebfce2c1d161186a82e77590bf7da2ea1bce91

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1552Unsecured Credentials
T1499Endpoint Denial of Service

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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