CVE-2023-4735Public exploit

Memory corruption via unbounded binary-number conversion

Published Sep 2, 2023 · Updated Jun 23, 2026

Out-of-bounds write in Vim before 9.0.1847 allows local users to corrupt process memory through crafted binary-number input. The do_addsub() conversion loop writes generated binary digits into fixed-size buf2 without limiting its index to the buffer length. A user must invoke an add or subtract command on the malicious value; Debian documents a CLI crash and no additional security impact.

CVSS severity4.8
Medium
EPSS probability0.60%
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 Vim before 9.0.1847 allows local users to corrupt process memory through crafted binary-number input. The do_addsub() conversion loop writes generated binary digits into fixed-size buf2 without limiting its index to the buffer length. A user must invoke an add or subtract command on the malicious value; Debian documents a CLI crash and no additional security impact.

The record

CVE
CVE-2023-4735
Published
Sep 2, 2023
Updated
Jun 23, 2026
Vendor
Vim
Product
Vim
Classifications
CWE-787, T1204.002
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 2, 2023CVE publishedPublication date reported by the CVE source.
  2. Jun 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=unspecified <9.0.1847

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Vim · Vimversion=unspecified <9.0.1847

Published CVSS scores

4.8huntr.devCVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L
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.

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

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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
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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