CVE-2021-4000

MEDIUMNVD 6.16.5▲

6.1

showdoc is vulnerable to URL Redirection to Untrusted Site

CVSS v3: 6.1
EG Score: 6.5(medium)
EPSS: 41.4%
KEV: Not listed

Published

December 3, 2021

Last Modified

November 21, 2024

References (4)

security@huntrhttps://github.com/star7th/showdoc/commit/c7f10033eba5f2b5a537f9af9ba2379138e67138
security@huntrhttps://huntr.dev/bounties/e4d803e0-3104-432c-80b3-34bc453c8962
af854a3a-2127-422b-91ae-364da2661108https://github.com/star7th/showdoc/commit/c7f10033eba5f2b5a537f9af9ba2379138e67138
af854a3a-2127-422b-91ae-364da2661108https://huntr.dev/bounties/e4d803e0-3104-432c-80b3-34bc453c8962

Patch Availability(1)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
composer	showdoc/showdoc	—	ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)

Packagist(1)

Package	Vulnerable range	Fixed in	Dependents
showdoc/showdoc	v1.0.0 ... v2.9.9 (131 versions)	—	—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-601URL Redirection to Untrusted Site (Open Redirect)

Data Freshness Timeline

(refreshed 10× in last 7d / 18× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-02 20:11 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-29 13:42 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 13:43 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 06:56 UTCEG score recompute
2026-05-26 06:56 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2021-4000?

CVE-2021-4000 is a medium vulnerability published on December 3, 2021. showdoc is vulnerable to URL Redirection to Untrusted Site

When was CVE-2021-4000 disclosed?

CVE-2021-4000 was first published in the National Vulnerability Database on December 3, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-4000 actively exploited?

CVE-2021-4000 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 41.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-4000?

CVE-2021-4000 has a CVSS v3 base score of 6.1 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 6.5.

How do I remediate CVE-2021-4000?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-4000, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-4000

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CVE-2021-4000

Published

Last Modified

References (4)

Patch Availability(1)

Affected Packages

Weakness Classification(1)

Data Freshness Timeline

Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-4000?

Same product

Same CWE

CVE-2021-4000

📅 Published

🔄 Last Modified

🔗 References (4)

Patch Availability(1)

Affected Packages

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-4000?

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References (4)

Frequently asked(5)

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