CVE-2022-0326

Compiler crash via invalid hash-update bytecode

Published Jan 21, 2022 · Updated Aug 2, 2024

NULL pointer dereference in mruby before 3.2 allows local users to crash the compiler by processing crafted Ruby code. The gen_hash code generator emits OP_HASHADD and adjusts the virtual stack even when a hash expression's value is discarded, leaving invalid bytecode state that reaches a null pointer. Execution of attacker-supplied Ruby source is required, and the demonstrated consequence is termination of the compiling or interpreting process rather than data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.81%
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 mruby before 3.2 allows local users to crash the compiler by processing crafted Ruby code. The gen_hash code generator emits OP_HASHADD and adjusts the virtual stack even when a hash expression's value is discarded, leaving invalid bytecode state that reaches a null pointer. Execution of attacker-supplied Ruby source is required, and the demonstrated consequence is termination of the compiling or interpreting process rather than data disclosure or modification.

The record

CVE
CVE-2022-0326
Published
Jan 21, 2022
Updated
Aug 2, 2024
Vendor
mruby
Product
mruby
Classifications
CWE-476, T1499
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 21, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=unspecified <3.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

mruby · mrubyversion=unspecified <3.2

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
5.5huntr.devCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
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.

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Technologies

Your stack

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Your stack

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