CVE-2023-52564

Local kernel crash via repeated DLCI release

Published Mar 2, 2024 · Updated May 23, 2026

NULL pointer dereference in the Linux kernel n_gsm line discipline allows local users to crash the kernel during tty teardown. gsm_cleanup_mux clears a DLCI pointer before gsm_dlci_release finishes, allowing repeated dlci_put calls while gsm_dlci_free remains pending and causing tty_port_put to dereference NULL. Exploitation requires low-privileged local access to trigger n_gsm teardown, and the documented consequence is an availability-only kernel fault.

CVSS severity5.5
Medium
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

NULL pointer dereference in the Linux kernel n_gsm line discipline allows local users to crash the kernel during tty teardown. gsm_cleanup_mux clears a DLCI pointer before gsm_dlci_release finishes, allowing repeated dlci_put calls while gsm_dlci_free remains pending and causing tty_port_put to dereference NULL. Exploitation requires low-privileged local access to trigger n_gsm teardown, and the documented consequence is an availability-only kernel fault.

The record

CVE
CVE-2023-52564
Published
Mar 2, 2024
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 2, 2024CVE publishedPublication date reported by the CVE source.
  2. May 23, 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=5.10.190 <5.10.198
  2. Affected versionversion=5138c228311a863c3cf937b94a3ab4c87f1f70c4 <a48d2bcd23f2c98d575bc2f9b7a3fbd16aeea9eb
  3. Affected versionversion=5.15.124 <5.15.134
  4. Affected versionversion=6.1.43 <6.1.56
  5. Affected versionversion=6.4.8 <6.5
  6. Affected versionversion=6.5
  7. Affected versionversion=74a8d6f50cc90ed0061997db51dfa81a62b0f835
  8. Affected versionversion=8fc0eabaa73bbd9bd705577071564616da5c8c61 <6d5c8862932d31a810b6545f7d69ecc124402c6e
  9. Affected versionversion=9615ca54bc138e35353a001e8b5d4824dce72188 <c61d0b87a7028c2c10faffc524d748334c7b9827
  10. Affected versionversion=9b9c8195f3f0d74a826077fc1c01b9ee74907239 <29346e217b8ab8a52889b88f00b268278d6b7668
  11. Affected versionversion=9b9c8195f3f0d74a826077fc1c01b9ee74907239 <2bff660e0ff349dee84dc4f6f6d10da4497f5b28

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.10.190 <5.10.198; version=5138c228311a863c3cf937b94a3ab4c87f1f70c4 <a48d2bcd23f2c98d575bc2f9b7a3fbd16aeea9eb; version=5.15.124 <5.15.134; version=6.1.43 <6.1.56; version=6.4.8 <6.5; version=6.5; version=74a8d6f50cc90ed0061997db51dfa81a62b0f835; version=8fc0eabaa73bbd9bd705577071564616da5c8c61 <6d5c8862932d31a810b6545f7d69ecc124402c6e; version=9615ca54bc138e35353a001e8b5d4824dce72188 <c61d0b87a7028c2c10faffc524d748334c7b9827; version=9b9c8195f3f0d74a826077fc1c01b9ee74907239 <29346e217b8ab8a52889b88f00b268278d6b7668; version=9b9c8195f3f0d74a826077fc1c01b9ee74907239 <2bff660e0ff349dee84dc4f6f6d10da4497f5b28

Published CVSS scores

5.5NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

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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