CVE-2026-72389Public exploit

Local code execution via dangling STP timer

Published Aug 15, 2026 · Updated Aug 15, 2026

Use-after-free in the Linux kernel bridge STP implementation allows local users to execute code through bridge teardown. br_topology_change_detection() arms the topology-change timer on an administratively down bridge without checking IFF_UP, while the deletion path frees the embedding net_device without synchronously canceling that timer. Exploitation requires CAP_NET_ADMIN, obtainable in user and network namespaces, and can corrupt kernel memory, crash the host, or hijack control flow.

CVSS severity7.8
High
EPSS probability0.16%
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 bridge STP implementation allows local users to execute code through bridge teardown. br_topology_change_detection() arms the topology-change timer on an administratively down bridge without checking IFF_UP, while the deletion path frees the embedding net_device without synchronously canceling that timer. Exploitation requires CAP_NET_ADMIN, obtainable in user and network namespaces, and can corrupt kernel memory, crash the host, or hijack control flow.

The record

CVE
CVE-2026-72389
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <297a747f59bff6573196d7236178144d66524e68
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2a00517db8de4be7df3d483b215c5544fb30a191
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <39283907a25e5caf0f2bd2947f6e56644b01e2b7
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <40cbfa3a28e0919469d1b086629bb3ce38a83593
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4c40eec06eeac37c58e47a6058eb32901218d5d4
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b4b3458ef88df4798632619f018791d4344bcd92
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c86579b0a2d201792bcb59316629f4ba4758cfc8
  8. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <297a747f59bff6573196d7236178144d66524e68; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2a00517db8de4be7df3d483b215c5544fb30a191; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <39283907a25e5caf0f2bd2947f6e56644b01e2b7; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <40cbfa3a28e0919469d1b086629bb3ce38a83593; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4c40eec06eeac37c58e47a6058eb32901218d5d4; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b4b3458ef88df4798632619f018791d4344bcd92; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c86579b0a2d201792bcb59316629f4ba4758cfc8; version=2.6.12

Published CVSS scores

7.0OracleCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8Linux CNACVSS: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 exploitPublished

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

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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