CVE-2023-52906

Kernel warning via mismatched MPLS attribute policy

Published Aug 21, 2024 · Updated May 11, 2026

Improper attribute validation in the Linux kernel allows local users to trigger a kernel warning through a malformed MPLS label. The act_mpls policy declares TCA_MPLS_LABEL as NLA_U32 while assigning a validation function, causing union-backed range fields to be interpreted as negative values when validation fails. A local user must reach the routing Netlink MPLS-action path; the published trace demonstrates a warning, not a crash, data access, or code execution.

CVSS severity7.8
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper attribute validation in the Linux kernel allows local users to trigger a kernel warning through a malformed MPLS label. The act_mpls policy declares TCA_MPLS_LABEL as NLA_U32 while assigning a validation function, causing union-backed range fields to be interpreted as negative values when validation fails. A local user must reach the routing Netlink MPLS-action path; the published trace demonstrates a warning, not a crash, data access, or code execution.

The record

CVE
CVE-2023-52906
Published
Aug 21, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 21, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=2a2ea50870baa3fb4de0872c5b60828138654ca7 <2b157c3c5d6b8ddca48d53c9e662032f65af8d61
  2. Affected versionversion=2a2ea50870baa3fb4de0872c5b60828138654ca7 <453277feb41c2235cf2c0de9209eef962c401457
  3. Affected versionversion=2a2ea50870baa3fb4de0872c5b60828138654ca7 <8a97b544b98e44f596219ebb290fd2ba2fd5d644
  4. Affected versionversion=2a2ea50870baa3fb4de0872c5b60828138654ca7 <9e17f99220d111ea031b44153fdfe364b0024ff2
  5. Affected versionversion=2a2ea50870baa3fb4de0872c5b60828138654ca7 <9e2c38827cdc6fdd3bb375c8607fc04d289756f9
  6. Affected versionversion=5.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2a2ea50870baa3fb4de0872c5b60828138654ca7 <2b157c3c5d6b8ddca48d53c9e662032f65af8d61; version=2a2ea50870baa3fb4de0872c5b60828138654ca7 <453277feb41c2235cf2c0de9209eef962c401457; version=2a2ea50870baa3fb4de0872c5b60828138654ca7 <8a97b544b98e44f596219ebb290fd2ba2fd5d644; version=2a2ea50870baa3fb4de0872c5b60828138654ca7 <9e17f99220d111ea031b44153fdfe364b0024ff2; version=2a2ea50870baa3fb4de0872c5b60828138654ca7 <9e2c38827cdc6fdd3bb375c8607fc04d289756f9; version=5.3

Published CVSS scores

7.8NIST NVDCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

No sourced classifications are available.

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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