CVE-2022-49940

Kernel crash via uninitialized receive callback

Published Jun 18, 2025 · Updated May 23, 2026

A null pointer dereference in Linux n_gsm allows local users to crash the kernel by sending data before GSM MUX activation. gsmld_receive_buf() invokes gsm->receive() without verifying that MUX initialization assigned the callback. Low-privileged local access to the affected TTY path is required, and exploitation interrupts the host by triggering a kernel null-pointer fault.

CVSS severity5.5
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A null pointer dereference in Linux n_gsm allows local users to crash the kernel by sending data before GSM MUX activation. gsmld_receive_buf() invokes gsm->receive() without verifying that MUX initialization assigned the callback. Low-privileged local access to the affected TTY path is required, and exploitation interrupts the host by triggering a kernel null-pointer fault.

The record

CVE
CVE-2022-49940
Published
Jun 18, 2025
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 18, 2025CVE 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=01aecd917114577c423f07cec0d186ad007d76fc <f16c6d2e58a4c2b972efcf9eb12390ee0ba3befb
  2. Affected versionversion=2dc1be365a70699f7dda92fd9e48b84546086070
  3. Affected versionversion=5.15.61 <5.15.66
  4. Affected versionversion=5.18.18 <5.19
  5. Affected versionversion=5.19.2 <5.19.8
  6. Affected versionversion=5e59c010c6862da329db17acca086afd8bea1aa8 <5aa37f9510345a812c0998bcbbc4d88d1dcc4d8b
  7. Affected versionversion=b8faa754b523a845facdc83120b2ecd290d7fa6d <5a82cf64f8ad63caf6bf115642ce44ddbc64311e
  8. Affected versionversion=dfa9b6d34aac2154b5e926d7a7a061123bf137c6 <309aea4b6b813f6678c3a547cfd7fe3a76ffa976

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=01aecd917114577c423f07cec0d186ad007d76fc <f16c6d2e58a4c2b972efcf9eb12390ee0ba3befb; version=2dc1be365a70699f7dda92fd9e48b84546086070; version=5.15.61 <5.15.66; version=5.18.18 <5.19; version=5.19.2 <5.19.8; version=5e59c010c6862da329db17acca086afd8bea1aa8 <5aa37f9510345a812c0998bcbbc4d88d1dcc4d8b; version=b8faa754b523a845facdc83120b2ecd290d7fa6d <5a82cf64f8ad63caf6bf115642ce44ddbc64311e; version=dfa9b6d34aac2154b5e926d7a7a061123bf137c6 <309aea4b6b813f6678c3a547cfd7fe3a76ffa976

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.0Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5Canonical Ubuntu SecurityCVSS: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
T1499.004Application or System Exploitation

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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