CVE-2021-4000

Open Redirect in star7th/showdoc

6.5 Medium

showdoc is vulnerable to URL Redirection to Untrusted Site

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: Low
Integrity: Low
Availability: None

Exploit likelihood

0.85%Up 0.2 points since Dec 4, 2021

What each source reports

CVE List Score used 6.5

Open Redirect in star7th/showdoc

showdoc is vulnerable to URL Redirection to Untrusted Site

Record: CVE-2021-4000
CVSS 3.0: 6.5 MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Weakness: CWE-601
Updated: 2026-11-02

EUVDEUVD-2021-2483 6.5

showdoc is vulnerable to URL Redirection to Untrusted Site

Record: EUVD-2021-2483
CVSS 3.0: 6.5 MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Updated: 2026-11-03

GitHub AdvisoriesGHSA-8c9x-wfgj-v78w 6.5

Open Redirect in showdoc

showdoc is vulnerable to URL Redirection to Untrusted Site

Record: GHSA-8c9x-wfgj-v78w
CVSS 3.0: 6.5 MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Weakness: CWE-601
Updated: 2026-11-02

NVD 6.1

showdoc is vulnerable to URL Redirection to Untrusted Site

Record: CVE-2021-4000
CVSS 3.1: 6.1 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS 3.0: 6.5 MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CVSS 2.0: 5.8 MediumAV:N/AC:M/Au:N/C:P/I:P/A:N
Weakness: CWE-601
Updated: 2026-11-02

OSV 6.1

showdoc is vulnerable to URL Redirection to Untrusted Site

Record: CVE-2021-4000
CVSS 3.1: 6.1 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Updated: 2026-11-02

OSVGHSA-8c9x-wfgj-v78w 6.5

Open Redirect in showdoc

showdoc is vulnerable to URL Redirection to Untrusted Site

Record: GHSA-8c9x-wfgj-v78w
CVSS 3.0: 6.5 MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Weakness: CWE-601
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`showdoc/showdoc` Packagist	through 2.9.13	None known
`showdoc/showdoc` Packagist	through 2.9.13, plus listed versions v1.0.0v1.0.1v1.0.2v1.0.3v1.0.4 Show 45 moreShow less v1.0.5v1.1.0v1.1.1v1.1.3v1.1.4v1.1.5v1.2.0v1.2.1v1.2.2v1.2.3v1.2.4v1.2.5v1.2.6v1.3.0v1.3.1v1.3.3v1.3.4v1.3.5v1.3.6v1.3.7v1.3.8v1.4.0v1.4.1v1.4.2v1.4.3v1.4.4v1.4.5v1.4.6v1.4.7v1.5.0v1.5.1v1.5.2v1.5.3v1.6.0v1.6.1v1.6.2v1.7.0v1.7.1v1.7.2v1.8.0v1.8.1v1.8.2v1.8.3v1.8.4v1.8.5	None known

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-4000 is a medium vulnerability (CVSS 6.5) in Showdoc, published December 3, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.85%, the 58th percentile. No source names a fixed version.

References

This page doesn't list everything

Left out here: 81 versions. The JSON record has them.