CVE-2026-53239

Kernel memory corruption via XFRM policy race

Published Jun 25, 2026 · Updated Jun 25, 2026

Use-after-free in the XFRM policy subsystem of Linux Kernel allows local users to corrupt kernel memory through concurrent Netlink operations. In xfrm_policy_bysel_ctx(), policy deletion drops xfrm_policy_lock before pruning an inexact-policy bin, while a concurrent SPD hash rebuild can free that bin and leave the pruning path to dereference stale memory. Reaching the race requires CAP_NET_ADMIN, including namespace-scoped access on systems that permit user-created network namespaces; exploitation can disclose or alter kernel data or crash the host.

CVSS severity7.8
High
EPSS probability0.17%
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 XFRM policy subsystem of Linux Kernel allows local users to corrupt kernel memory through concurrent Netlink operations. In xfrm_policy_bysel_ctx(), policy deletion drops xfrm_policy_lock before pruning an inexact-policy bin, while a concurrent SPD hash rebuild can free that bin and leave the pruning path to dereference stale memory. Reaching the race requires CAP_NET_ADMIN, including namespace-scoped access on systems that permit user-created network namespaces; exploitation can disclose or alter kernel data or crash the host.

The record

CVE
CVE-2026-53239
Published
Jun 25, 2026
Updated
Jun 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 25, 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=5.0
  2. Affected versionversion=6be3b0db6db82cf056a72cc18042048edd27f8ee <25c8c7fb3b0b9668c7d05e209f58c158d2b020c7
  3. Affected versionversion=6be3b0db6db82cf056a72cc18042048edd27f8ee <42827d03f8009a6a218bacab153e21f39d6a121c
  4. Affected versionversion=6be3b0db6db82cf056a72cc18042048edd27f8ee <7f2d76c9c03257c0782afef9d95321fa04096f60
  5. Affected versionversion=6be3b0db6db82cf056a72cc18042048edd27f8ee <88697cf980222d5906a37bf47662dac0732e2a0f
  6. Affected versionversion=6be3b0db6db82cf056a72cc18042048edd27f8ee <8fc536e9f6856230f19c7d13e71af064b6a77b22
  7. Affected versionversion=6be3b0db6db82cf056a72cc18042048edd27f8ee <b5316e2b8614a87d8736941972441cb47bfd4491
  8. Affected versionversion=6be3b0db6db82cf056a72cc18042048edd27f8ee <c4c1ea36d83bf3c4569468ca5b8b614fda1bf821
  9. Affected versionversion=6be3b0db6db82cf056a72cc18042048edd27f8ee <ec82ea4eb220164d854f8734ca5a35e23e577b94

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.0; version=6be3b0db6db82cf056a72cc18042048edd27f8ee <25c8c7fb3b0b9668c7d05e209f58c158d2b020c7; version=6be3b0db6db82cf056a72cc18042048edd27f8ee <42827d03f8009a6a218bacab153e21f39d6a121c; version=6be3b0db6db82cf056a72cc18042048edd27f8ee <7f2d76c9c03257c0782afef9d95321fa04096f60; version=6be3b0db6db82cf056a72cc18042048edd27f8ee <88697cf980222d5906a37bf47662dac0732e2a0f; version=6be3b0db6db82cf056a72cc18042048edd27f8ee <8fc536e9f6856230f19c7d13e71af064b6a77b22; version=6be3b0db6db82cf056a72cc18042048edd27f8ee <b5316e2b8614a87d8736941972441cb47bfd4491; version=6be3b0db6db82cf056a72cc18042048edd27f8ee <c4c1ea36d83bf3c4569468ca5b8b614fda1bf821; version=6be3b0db6db82cf056a72cc18042048edd27f8ee <ec82ea4eb220164d854f8734ca5a35e23e577b94

Published CVSS scores

7.8LinuxCVSS: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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