How severe is CVE-2021-3993?

CVE-2021-3993 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2021-3993 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3993?

CVE-2021-3993 affects Showdoc. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-3993?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-3993 published?

CVE-2021-3993 was published on 2021-12-01 and last updated on 2026-06-17.

CVE-2021-3993

CVE-2021-3993 is a medium-severity vulnerability in Showdoc with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-352.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 1% (40th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-352
Affected product: Showdoc
Published: 2021-12-01
Last modified: 2026-06-17

Description

showdoc is vulnerable to Cross-Site Request Forgery (CSRF)

Frequently asked questions

What is CVE-2021-3993?: showdoc is vulnerable to Cross-Site Request Forgery (CSRF)
How severe is CVE-2021-3993?: CVE-2021-3993 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2021-3993 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3993?: CVE-2021-3993 affects Showdoc. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-3993?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-3993 published?: CVE-2021-3993 was published on 2021-12-01 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:showdoc:showdoc:*:*:*:*:*:*:*:*

More vulnerabilities in Showdoc

CVE-2022-0362 — Critical (CVSS 9.8): SQL Injection in Packagist showdoc/showdoc prior to 2.10.3.
CVE-2021-41745 — Critical (CVSS 9.8): ShowDoc 2.8.3 ihas a file upload vulnerability, where attackers can use the vulnerability to obtain server permissions.
CVE-2021-36440 — Critical (CVSS 9.8): Unrestricted File Upload in ShowDoc v2.9.5 allows remote attackers to execute arbitrary code via the 'file_url'…
CVE-2021-4168 — High (CVSS 8.8): showdoc is vulnerable to Cross-Site Request Forgery (CSRF)
CVE-2021-4017 — High (CVSS 8.8): showdoc is vulnerable to Cross-Site Request Forgery (CSRF)
CVE-2022-0409 — High (CVSS 7.8): Unrestricted Upload of File with Dangerous Type in Packagist showdoc/showdoc prior to 2.10.2.

All CVEs affecting Showdoc →

Other CWE-352 (Cross-Site Request Forgery (CSRF)) vulnerabilities

CVE-2025-32642 — Critical (CVSS 10.0): Cross-Site Request Forgery (CSRF) vulnerability in appsbd Vite Coupon vite-coupon allows Remote Code Inclusion.This…
CVE-2025-23922 — Critical (CVSS 10.0): Cross-Site Request Forgery (CSRF) vulnerability in Harsh iSpring Embedder embed-ispring allows Upload a Web Shell to a…
CVE-2017-5145 — Critical (CVSS 10.0): An issue was discovered in Carlo Gavazzi VMU-C EM prior to firmware Version A11_U05, and VMU-C PV prior to firmware…
CVE-2019-25729 — Critical (CVSS 9.8): PDF Signer 3.0 contains a server-side template injection vulnerability that allows unauthenticated attackers to execute…
CVE-2025-48340 — Critical (CVSS 9.8): Cross-Site Request Forgery (CSRF) vulnerability in Danny Vink User Profile Meta Manager user-profile-meta allows…
CVE-2025-2907 — Critical (CVSS 9.8): The Order Delivery Date WordPress plugin before 12.3.1 does not have authorization and CSRF checks when importing…

Browse all CWE-352 (Cross-Site Request Forgery (CSRF)) vulnerabilities →