CVE-2023-1829Public exploit

Local root escalation via undeactivated perfect-hash filter

Published Apr 12, 2023 · Updated Jul 29, 2026

Use-after-free in the Linux Kernel tcindex classifier allows local users to gain root privileges by deleting a perfect-hash filter. The tcindex_delete function destroys a perfect-hash result extension without deactivating its filter, leaving freed action pointers reachable for a second free. Exploitation requires CAP_NET_ADMIN, obtainable through enabled unprivileged user namespaces, plus CONFIG_NET_CLS_TCINDEX; successful exploitation grants root access.

CVSS severity7.8
High
EPSS probability1.04%
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 tcindex classifier allows local users to gain root privileges by deleting a perfect-hash filter. The tcindex_delete function destroys a perfect-hash result extension without deactivating its filter, leaving freed action pointers reachable for a second free. Exploitation requires CAP_NET_ADMIN, obtainable through enabled unprivileged user namespaces, plus CONFIG_NET_CLS_TCINDEX; successful exploitation grants root access.

The record

CVE
CVE-2023-1829
Published
Apr 12, 2023
Updated
Jul 29, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 12, 2023CVE publishedPublication date reported by the CVE source.
  2. Jul 29, 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=3.8.0 <4.14.308
  2. Affected versionversion=4.15.0 <4.19.276
  3. Affected versionversion=4.20.0 <5.4.235
  4. Affected versionversion=5.11.0 <5.15.100
  5. Affected versionversion=5.16.0 <6.1.18
  6. Affected versionversion=5.5.0 <5.10.173
  7. Affected versionversion=6.2.0 <6.2.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.8.0 <4.14.308; version=4.15.0 <4.19.276; version=4.20.0 <5.4.235; version=5.11.0 <5.15.100; version=5.16.0 <6.1.18; version=5.5.0 <5.10.173; version=6.2.0 <6.2.5

Published CVSS scores

7.8Google 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.

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

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

CWE-416Use After Free
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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