CVE-2023-35126Public exploit

Code execution via unchecked style-record index

Published Oct 19, 2023 · Updated Feb 13, 2025

Out-of-bounds write in JustSystems Ichitaro 2023 1.0.1.59372 allows attackers to execute code through a crafted JTD document. The DocumentViewStyles and DocumentEditStyles parsers use an unvalidated 16-bit sub-record index to select an element from a six-entry stack array before writing decoded data. A user must open the document; Talos reports code execution in the application context, while JustSystems reports only forced termination.

CVSS severity7.8
High
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in JustSystems Ichitaro 2023 1.0.1.59372 allows attackers to execute code through a crafted JTD document. The DocumentViewStyles and DocumentEditStyles parsers use an unvalidated 16-bit sub-record index to select an element from a six-entry stack array before writing decoded data. A user must open the document; Talos reports code execution in the application context, while JustSystems reports only forced termination.

The record

CVE
CVE-2023-35126
Published
Oct 19, 2023
Updated
Feb 13, 2025
Vendor
JustSystems
Product
Ichitaro
Classifications
CWE-129, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 19, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.0.1.59372

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

JustSystems · Ichitaroversion=1.0.1.59372

Published CVSS scores

1.9JPCERT/CC and IPAAV:L/AC:M/Au:N/C:N/I:N/A:P
3.3JPCERT/CC and IPACVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
7.8Cisco TalosCVSS: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-129Improper Validation of Array Index
T1204.002User Execution: Malicious File

Public exploit references

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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