CVE-2022-38223Public exploit

Crash via stale multibyte backspace length

Published Aug 15, 2022 · Updated Nov 4, 2025

An out-of-bounds write in w3m 0.5.3 allows context-dependent attackers to crash the browser through a crafted HTML file. In etc.c, checkType reuses a stale multibyte character length while processing backspaces, causing the line-property pointer to retreat too far before a subsequent write. A user must open the crafted file in a multibyte-enabled build; the demonstrated result is a crash, while other impact remains unspecified.

CVSS severity7.8
High
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An out-of-bounds write in w3m 0.5.3 allows context-dependent attackers to crash the browser through a crafted HTML file. In etc.c, checkType reuses a stale multibyte character length while processing backspaces, causing the line-property pointer to retreat too far before a subsequent write. A user must open the crafted file in a multibyte-enabled build; the demonstrated result is a crash, while other impact remains unspecified.

The record

CVE
CVE-2022-38223
Published
Aug 15, 2022
Updated
Nov 4, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2022CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1204.002Malicious File

Public exploit references

  • poc0.zipproof of concept · demonstrated

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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