CVE-2023-52621

Kernel warning via incorrect BPF lock assertion

Published Mar 26, 2024 · Updated May 11, 2026

Improper lock-state validation in the Linux kernel allows local users to trigger a kernel warning through a sleepable BPF program. The bpf_map_lookup_elem, bpf_map_update_elem, and bpf_map_delete_elem helpers accept sleepable programs but test only ordinary RCU lock state, incorrectly rejecting the held RCU Tasks Trace lock. The condition requires BPF interpreter mode with bpf_jit_enable set to 0 and sufficient privileges to load and run the program; the published reproducer reports a warning rather than a confirmed crash.

CVSS severity7.8
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper lock-state validation in the Linux kernel allows local users to trigger a kernel warning through a sleepable BPF program. The bpf_map_lookup_elem, bpf_map_update_elem, and bpf_map_delete_elem helpers accept sleepable programs but test only ordinary RCU lock state, incorrectly rejecting the held RCU Tasks Trace lock. The condition requires BPF interpreter mode with bpf_jit_enable set to 0 and sufficient privileges to load and run the program; the published reproducer reports a warning rather than a confirmed crash.

The record

CVE
CVE-2023-52621
Published
Mar 26, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 26, 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=1e6c62a8821557720a9b2ea9617359b264f2f67c <169410eba271afc9f0fb476d996795aa26770c6d
  2. Affected versionversion=1e6c62a8821557720a9b2ea9617359b264f2f67c <3516f93cc63d956e1b290ae4b7bf2586074535a0
  3. Affected versionversion=1e6c62a8821557720a9b2ea9617359b264f2f67c <483cb92334cd7f1d5387dccc0ab5d595d27a669d
  4. Affected versionversion=1e6c62a8821557720a9b2ea9617359b264f2f67c <82f2df94dac1aa9b879e74d1f82ba1b631bdc612
  5. Affected versionversion=1e6c62a8821557720a9b2ea9617359b264f2f67c <c7f1b6146f4a46d727c0d046284c28b6882c6304
  6. Affected versionversion=1e6c62a8821557720a9b2ea9617359b264f2f67c <d6d6fe4bb105595118f12abeed4a7bdd450853f3
  7. Affected versionversion=5.10

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1e6c62a8821557720a9b2ea9617359b264f2f67c <169410eba271afc9f0fb476d996795aa26770c6d; version=1e6c62a8821557720a9b2ea9617359b264f2f67c <3516f93cc63d956e1b290ae4b7bf2586074535a0; version=1e6c62a8821557720a9b2ea9617359b264f2f67c <483cb92334cd7f1d5387dccc0ab5d595d27a669d; version=1e6c62a8821557720a9b2ea9617359b264f2f67c <82f2df94dac1aa9b879e74d1f82ba1b631bdc612; version=1e6c62a8821557720a9b2ea9617359b264f2f67c <c7f1b6146f4a46d727c0d046284c28b6882c6304; version=1e6c62a8821557720a9b2ea9617359b264f2f67c <d6d6fe4bb105595118f12abeed4a7bdd450853f3; version=5.10

Published CVSS scores

4.4Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
7.8CanonicalCVSS: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

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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

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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