CVE-2026-28417

Command execution via unanchored hostname validation

Published Feb 27, 2026 · Updated Feb 27, 2026

OS command injection in Vim before 9.2.0073 allows attackers to execute shell commands by inducing a user to open a crafted netrw URL. The s:NetrwValidateHostname() function accepts a hostname when only its first character is alphanumeric, leaving later shell metacharacters unescaped when netrw builds a command for :r!. Exploitation requires the user to open the malicious URL, and injected commands run with the privileges of the Vim process.

CVSS severity4.4
Medium
EPSS probability1.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in Vim before 9.2.0073 allows attackers to execute shell commands by inducing a user to open a crafted netrw URL. The s:NetrwValidateHostname() function accepts a hostname when only its first character is alphanumeric, leaving later shell metacharacters unescaped when netrw builds a command for :r!. Exploitation requires the user to open the malicious URL, and injected commands run with the privileges of the Vim process.

The record

CVE
CVE-2026-28417
Published
Feb 27, 2026
Updated
Feb 27, 2026
Vendor
Vim
Product
Vim
Classifications
CWE-78, CWE-86, T1204.001
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 27, 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=< 9.2.0073

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Vim · Vimversion=< 9.2.0073

Published CVSS scores

4.4GitHubCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
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 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-78Improper Neutralization of Special Elements used in an OS Command
CWE-86Improper Neutralization of Invalid Characters in Identifiers in Web Pages
T1204.001User Execution: Malicious Link

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

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Your stack

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