CVE-2026-22781: TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32

Q: How do I fix CVE-2026-22781?

tinyweb: upgrade to 1.98. Exact commands for each OS are on this page.

Q: Is CVE-2026-22781 being exploited?

CVE-2026-22781 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-22781 affect?

CVE-2026-22781 affects tinyweb. Severity is critical (CVSS 9.8). 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 argumen

Q: How urgent is CVE-2026-22781?

Priority 63/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2026-22781 is a critical-severity flaw (CVSS 9.8) affecting tinyweb. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 vulnerabi

Why this priority

Critical severity
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.4% (top 16%)
CISA exploited list	No
Weakness	CWE-78
Published	2026-01-12
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: ritlabs

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-01-12 19:16 UTCPublished CVE record published
2026-06-17 10:20 UTCUpdated Record last modified

ritlabs tinyweb UPGRADE

Affected: < 1.98

Fixed in: 1.98

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy tinyweb || rpm -q tinyweb || tinyweb --version

2. UPGRADE to 1.98 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade tinyweb

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade tinyweb

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Fedora 46 · jgmenu · FIXED · 4.7.0-1.fc46 · FEDORA-2026-3053ee4399 · source

sudo dnf upgrade --advisory=FEDORA-2026-3053ee4399

Fedora ELN · python-tkrzw · FIXED · 0.1.32-12.eln159 · FEDORA-2026-0161d71544 · source

sudo dnf upgrade --advisory=FEDORA-2026-0161d71544

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-22781?

tinyweb: upgrade to 1.98. Exact commands for each OS are on this page.

Is CVE-2026-22781 being exploited?

CVE-2026-22781 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-22781 affect?

CVE-2026-22781 affects tinyweb. Severity is critical (CVSS 9.8). 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 argumen

How urgent is CVE-2026-22781?

Priority 63/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

Windows vulnerabilities

Related CVEs

CVE-2026-29046 HIGH 8.2 UPGRADE TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32
CVE-2026-28497 CRITICAL 9.1 UPGRADE TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32
CVE-2026-27633 HIGH 7.5 UPGRADE TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32
CVE-2026-27630 HIGH 7.5 UPGRADE TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32
CVE-2026-27613 CRITICAL 9.8 UPGRADE TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32

References

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