CVE-2026-27613Public exploitNetwork attack vector

Remote code execution via CGI argument injection

Published Feb 25, 2026 · Updated Feb 25, 2026

Argument injection in TinyWeb Server before 2.01 allows remote attackers to disclose CGI source code or execute code via HTTP requests. In SrvMain.pas, IsQueryParamSafe accepts leading hyphens and EscapeShellParam applies cmd.exe caret escaping to quotes passed to native Win32 CGI binaries. CGI must be enabled: the default strict mode exposes PHP source through the -s flag, while disabling it permits arbitrary PHP flags and code execution.

CVSS severity9.3
Critical
EPSS probability0.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Argument injection in TinyWeb Server before 2.01 allows remote attackers to disclose CGI source code or execute code via HTTP requests. In SrvMain.pas, IsQueryParamSafe accepts leading hyphens and EscapeShellParam applies cmd.exe caret escaping to quotes passed to native Win32 CGI binaries. CGI must be enabled: the default strict mode exposes PHP source through the -s flag, while disabling it permits arbitrary PHP flags and code execution.

The record

CVE
CVE-2026-27613
Published
Feb 25, 2026
Updated
Feb 25, 2026
Vendor
Maxim Masiutin
Product
TinyWeb Server
Classifications
CWE-88, CWE-78, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 25, 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=< 2.01

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Maxim Masiutin · TinyWeb Serverversion=< 2.01

Published CVSS scores

9.3Maxim MasiutinCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-88Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1190Exploit Public-Facing Application

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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