CVE-2026-76149

Dictionary-file corruption via TAR size overflow

Published Aug 26, 2026 · Updated Aug 26, 2026

Integer overflow in CorvusSKK before 3.3.4 allows local users to write malicious data to a legitimate dictionary file via a crafted TAR archive. The TAR importer represents an archive member's file size as a signed 32-bit integer, allowing an oversized size value to overflow during extraction. A user must cause the affected IME to import the crafted archive; the reported consequence is dictionary-file modification, not code execution.

CVSS severity4.6
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Integer overflow in CorvusSKK before 3.3.4 allows local users to write malicious data to a legitimate dictionary file via a crafted TAR archive. The TAR importer represents an archive member's file size as a signed 32-bit integer, allowing an oversized size value to overflow during extraction. A user must cause the affected IME to import the crafted archive; the reported consequence is dictionary-file modification, not code execution.

The record

CVE
CVE-2026-76149
Published
Aug 26, 2026
Updated
Aug 26, 2026
Vendor
SASAKI Nobuyuki
Product
CorvusSKK
Classifications
CWE-190, T1565.001
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <3.3.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

SASAKI Nobuyuki · CorvusSKKversion=0 <3.3.4

Published CVSS scores

4.6JPCERT/CC and IPACVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
4.4JPCERT/CC and IPACVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
T1565.001Stored Data Manipulation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo