CVE-2026-46319

Local privilege escalation via premature RCU unlock

Published Jun 9, 2026 · Updated Jun 9, 2026

Use-after-free in the Linux Kernel act_ct scheduler allows local users with CAP_NET_ADMIN to escalate privileges through traffic-control configuration. tcf_ct_flow_table_get releases the RCU read lock before incrementing the returned ct_ft reference, allowing cleanup work to free the object during the intervening race window. Concurrent traffic-control netlink operations on a shared zone are required; successful exploitation grants kernel-level privileges.

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

Use-after-free in the Linux Kernel act_ct scheduler allows local users with CAP_NET_ADMIN to escalate privileges through traffic-control configuration. tcf_ct_flow_table_get releases the RCU read lock before incrementing the returned ct_ft reference, allowing cleanup work to free the object during the intervening race window. Concurrent traffic-control netlink operations on a shared zone are required; successful exploitation grants kernel-level privileges.

The record

CVE
CVE-2026-46319
Published
Jun 9, 2026
Updated
Jun 9, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 9, 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=138470a9b2cc2e26e6018300394afc3858a54e6a <17dfb67cb399b660105d9a8c6100851c0d0cdc70
  2. Affected versionversion=138470a9b2cc2e26e6018300394afc3858a54e6a <3e20e1b3058e0b94638e7b931c138e840e266724
  3. Affected versionversion=138470a9b2cc2e26e6018300394afc3858a54e6a <4c727c6967a41b37efe0f26332ca9ec5b74785a3
  4. Affected versionversion=138470a9b2cc2e26e6018300394afc3858a54e6a <67c9ecc9f2575273ed1323e312881fc98ac83d6d
  5. Affected versionversion=138470a9b2cc2e26e6018300394afc3858a54e6a <a2e0c045c87aa252eb61412e67dd91f2c2b19f81
  6. Affected versionversion=138470a9b2cc2e26e6018300394afc3858a54e6a <ece578ca61e572df96cfc80456357ebfae0b4b9e
  7. Affected versionversion=138470a9b2cc2e26e6018300394afc3858a54e6a <f23424a0ddadb494d4bd57056a7ca703312d3a7b
  8. Affected versionversion=138470a9b2cc2e26e6018300394afc3858a54e6a <f462dca0c8415bf0058d0ffa476354c4476d0f09
  9. Affected versionversion=5.7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=138470a9b2cc2e26e6018300394afc3858a54e6a <17dfb67cb399b660105d9a8c6100851c0d0cdc70; version=138470a9b2cc2e26e6018300394afc3858a54e6a <3e20e1b3058e0b94638e7b931c138e840e266724; version=138470a9b2cc2e26e6018300394afc3858a54e6a <4c727c6967a41b37efe0f26332ca9ec5b74785a3; version=138470a9b2cc2e26e6018300394afc3858a54e6a <67c9ecc9f2575273ed1323e312881fc98ac83d6d; version=138470a9b2cc2e26e6018300394afc3858a54e6a <a2e0c045c87aa252eb61412e67dd91f2c2b19f81; version=138470a9b2cc2e26e6018300394afc3858a54e6a <ece578ca61e572df96cfc80456357ebfae0b4b9e; version=138470a9b2cc2e26e6018300394afc3858a54e6a <f23424a0ddadb494d4bd57056a7ca703312d3a7b; version=138470a9b2cc2e26e6018300394afc3858a54e6a <f462dca0c8415bf0058d0ffa476354c4476d0f09; version=5.7

Published CVSS scores

7.8kernel.orgCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

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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