CVE-2021-4172

Cross-site Scripting (XSS) - Stored in star7th/showdoc

6.5 MediumFix available

Cross-site Scripting (XSS) - Stored in GitHub repository star7th/showdoc prior to 2.10.2.

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

0.64%Unchanged since Jan 23, 2022

What each source reports

CVE List Score used 6.5

Cross-site Scripting (XSS) - Stored in star7th/showdoc

Cross-site Scripting (XSS) - Stored in GitHub repository star7th/showdoc prior to 2.10.2.

Record: CVE-2021-4172
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-79
Updated: 2026-11-02

EUVDEUVD-2022-0895 6.5

Cross-site Scripting (XSS) - Stored in GitHub repository star7th/showdoc prior to 2.10.2.

Record: EUVD-2022-0895
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-7x22-pmw5-66mq 5.4

Cross-site Scripting in showdoc

Stored XSS via upload attachment with format .svg in File Library.

Record: GHSA-7x22-pmw5-66mq
CVSS 3.1: 5.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

NVD 5.4

Cross-site Scripting (XSS) - Stored in GitHub repository star7th/showdoc prior to 2.10.2.

Record: CVE-2021-4172
CVSS 3.1: 5.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/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: 3.5 LowAV:N/AC:M/Au:S/C:N/I:P/A:N
Weakness: CWE-79
Updated: 2026-11-02

OSV 5.4

Cross-site Scripting (XSS) - Stored in GitHub repository star7th/showdoc prior to 2.10.2.

Record: CVE-2021-4172
CVSS 3.1: 5.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Updated: 2026-11-02

OSVGHSA-7x22-pmw5-66mq 5.4

Cross-site Scripting in showdoc

Stored XSS via upload attachment with format .svg in File Library.

Record: GHSA-7x22-pmw5-66mq
CVSS 3.1: 5.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`showdoc/showdoc` Packagist	before 2.10.2	2.10.2
`showdoc/showdoc` Packagist	before 2.10.2, 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	2.10.2

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-2021-4172 is a medium vulnerability (CVSS 6.5) in Showdoc, published January 22, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.64%, the 50th percentile. Fixed in showdoc/showdoc 2.10.2.

References

This page doesn't list everything

Left out here: 85 versions. The JSON record has them.