CVE-2026-39881

Arbitrary Ex command execution via unsanitized messages

Published Apr 8, 2026 · Updated Apr 8, 2026

Command injection in the NetBeans interface in Vim before 9.2.0316 allows attackers to execute arbitrary Ex commands via protocol messages. The defineAnnoType handler interpolates typeName, fg, and bg into coloncmd(), while specialKeys places unchecked tokens in a map command, allowing separators to alter command syntax. Exploitation requires a user to start Vim with -nb pointed at an attacker-controlled server, after which injected Ex commands can read or write files and invoke system commands.

CVSS severity5.0
Medium
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in the NetBeans interface in Vim before 9.2.0316 allows attackers to execute arbitrary Ex commands via protocol messages. The defineAnnoType handler interpolates typeName, fg, and bg into coloncmd(), while specialKeys places unchecked tokens in a map command, allowing separators to alter command syntax. Exploitation requires a user to start Vim with -nb pointed at an attacker-controlled server, after which injected Ex commands can read or write files and invoke system commands.

The record

CVE
CVE-2026-39881
Published
Apr 8, 2026
Updated
Apr 8, 2026
Vendor
Vim
Product
Vim
Classifications
CWE-94, T1059
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 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=< 9.2.0316

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Vim · Vimversion=< 9.2.0316

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
5.0GitHub, Inc.CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:H/A:N

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
T1059Command and Scripting Interpreter

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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