dbcve.org
TinywebApplication · Ritlabs

CVE-2026-22781

CRITICAL · 9.8 CVSS v3.1 Published 2026-01-12
Fix available
A fix is available. Upgrade to 1.98 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32. TinyWeb HTTP Server before version 1.98 is vulnerable to OS command injection via CGI ISINDEX-style query parameters. The query parameters are passed as command-line arguments to the CGI executable via Windows CreateProcess(). An unauthenticated remote attacker can execute arbitrary commands on the server by injecting Windows shell metacharacters into HTTP requests. This vulnerability is fixed in 1.98.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

TinyWeb HTTP Server versions before 1.98 contain an OS command injection vulnerability in CGI handling. The server passes query parameters from ISINDEX-style HTTP requests as command-line arguments to CGI executables via Windows CreateProcess(). By injecting Windows shell metacharacters into these query parameters, unauthenticated remote attackers can execute arbitrary operating system commands on the server.

MitigationUpgrade TinyWeb HTTP Server to version 1.98 or later. If immediate patching is not possible, disable or restrict access to CGI functionality at the network perimeter until the upgrade can be completed.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
TinywebApplication
Affected:< 1.98

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify TinyWeb HTTP Server installation and version
    Check for TinyWeb executable (tinyweb.exe or tinyweb64.exe) in common installation paths such as C:\Program Files\Tinyweb, C:\Tinyweb, or the server's root directory. Right-click the executable, select Properties, and examine the Version tab to obtain the precise version number. Alternatively, run 'tinyweb.exe -v' or check the server's HTTP response headers for the Server field which may disclose the version.
    Affected if The installed version is below 1.98 (for example, 1.95, 1.96, or 1.97). Compare your version against the affected range of versions less than 1.98.
  2. Determine if CGI functionality is enabled
    Locate the TinyWeb configuration file (typically tinyweb.conf in the same directory as the executable). Open it in a text editor and search for lines containing 'cgi' or 'cgi-bin'. Also examine the file system for a 'cgi-bin' or 'cgi' folder in the TinyWeb root directory.
    Affected if CGI is enabled, indicated by a CGI-related directive in the configuration file or the presence of a cgi-bin directory with executable scripts.
  3. Verify CGI scripts are network-accessible
    Confirm that the CGI bin directory is accessible over the network by checking the TinyWeb configuration for any IP-based access restrictions (look for 'allow' or 'deny' directives). Attempt a local HTTP request to a known CGI script endpoint (such as http://localhost/cgi-bin/scriptname.exe) or check network firewall rules to determine if port 80/443 is exposed.
    Affected if The CGI functionality is exposed to untrusted network access, meaning the server is reachable from the network and CGI scripts can be invoked without authentication.

You are affected if you are running TinyWeb HTTP Server version 1.97 or earlier with CGI functionality enabled and accessible to potential attackers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.98 or later
Fixed in 1.98
Vendor patch github.com →
Interim mitigation

Upgrade TinyWeb HTTP Server to version 1.98 or later. If immediate patching is not possible, disable or restrict access to CGI functionality at the network perimeter until the upgrade can be completed.

Recommended fix High confidence

TinyWeb version 1.98

  1. 1. Identify the currently running TinyWeb version by checking the server banner or executable file properties
  2. 2. Navigate to the official TinyWeb GitHub repository at github.com/maximmasiutin/TinyWeb
  3. 3. Download the version 1.98 release package (or latest version >= 1.98)
  4. 4. Backup the current TinyWeb installation directory, including configuration files and any web content
  5. 5. Stop the TinyWeb service if it is currently running
  6. 6. Replace the existing TinyWeb executable and associated files with the new version 1.98 files
  7. 7. Restore any custom configuration files from the backup
  8. 8. Start the TinyWeb service and verify it is running correctly

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Tinyweb Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,920
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-22781 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data