CVE-2026-52931Network attack vector

Undefined behavior via uninitialized sender-state access

Published Jun 24, 2026 · Updated Jun 24, 2026

Use of uninitialized state in the Linux Kernel batman-adv tp_meter subsystem allows remote attackers to trigger undefined behavior via an ACK packet. The batadv_tp_recv_ack() and batadv_tp_stop() paths read sender-only tp_vars members after resolving a receiver-role session, although those members were never initialized for that role. Reachability requires an ongoing tp_meter receiver session and a malicious ACK packet; Linux has not specified whether the resulting undefined behavior causes a crash, disclosure, or corruption.

CVSS severity9.8
Critical
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use of uninitialized state in the Linux Kernel batman-adv tp_meter subsystem allows remote attackers to trigger undefined behavior via an ACK packet. The batadv_tp_recv_ack() and batadv_tp_stop() paths read sender-only tp_vars members after resolving a receiver-role session, although those members were never initialized for that role. Reachability requires an ongoing tp_meter receiver session and a malicious ACK packet; Linux has not specified whether the resulting undefined behavior causes a crash, disclosure, or corruption.

The record

CVE
CVE-2026-52931
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
Unavailable
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 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=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <0e388af04b3958b178a1b979527f93eb46ea1fee
  2. Affected versionversion=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <1a21c055f66e78973712a4a1be2a554f1ee2e4f4
  3. Affected versionversion=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <53f931e0146ae5bdab4cba302646827d06b3794b
  4. Affected versionversion=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <6c65cf23d4c6170fcf5714c32aa64689718cb142
  5. Affected versionversion=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <85397e48afe6be83ffca5ad3f4792296bfc81d3d
  6. Affected versionversion=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <9884c9c02d3c90e9215db3c5128f59045d20ae91
  7. Affected versionversion=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <dc2ae5fbd2dadc26735092f140b246841d969a11
  8. Affected versionversion=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <ecdaa3e4d91040206afe21bc8a0d1198a0971ff3
  9. Affected versionversion=4.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <0e388af04b3958b178a1b979527f93eb46ea1fee; version=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <1a21c055f66e78973712a4a1be2a554f1ee2e4f4; version=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <53f931e0146ae5bdab4cba302646827d06b3794b; version=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <6c65cf23d4c6170fcf5714c32aa64689718cb142; version=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <85397e48afe6be83ffca5ad3f4792296bfc81d3d; version=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <9884c9c02d3c90e9215db3c5128f59045d20ae91; version=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <dc2ae5fbd2dadc26735092f140b246841d969a11; version=33a3bb4a3345bb511f9c69c913da95d4693e2a4e <ecdaa3e4d91040206afe21bc8a0d1198a0971ff3; version=4.8

Published CVSS scores

6.5Amazon LinuxCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
9.8LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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