CVE-2026-22781Public exploitNetwork attack vector

Unauthenticated command execution via unescaped CGI arguments

Published Jan 12, 2026 · Updated Jan 12, 2026

OS command injection in Maxim Masiutin TinyWeb before 1.98 allows remote attackers to execute arbitrary commands through crafted HTTP requests. The ExecuteScript function appends decoded ISINDEX-style query input directly to a CGI command line without escaping Windows shell metacharacters before CreateProcess runs it. A reachable CGI script under cgi-bin is required; successful requests run commands with the server process's privileges without authentication or user interaction.

CVSS severity10.0
Critical
EPSS probability2.47%
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 Maxim Masiutin TinyWeb before 1.98 allows remote attackers to execute arbitrary commands through crafted HTTP requests. The ExecuteScript function appends decoded ISINDEX-style query input directly to a CGI command line without escaping Windows shell metacharacters before CreateProcess runs it. A reachable CGI script under cgi-bin is required; successful requests run commands with the server process's privileges without authentication or user interaction.

The record

CVE
CVE-2026-22781
Published
Jan 12, 2026
Updated
Jan 12, 2026
Vendor
Maxim Masiutin
Product
TinyWeb
Classifications
CWE-78, T1059.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 12, 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=< 1.98

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Maxim Masiutin · TinyWebversion=< 1.98

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
10.0GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA: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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059.003Windows Command Shell

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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