How severe is CVE-2021-3944?

CVE-2021-3944 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-3944 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3944?

CVE-2021-3944 affects Bookstackapp Bookstack. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-3944?

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

When was CVE-2021-3944 published?

CVE-2021-3944 was published on 2021-12-02 and last updated on 2026-06-17.

CVE-2021-3944

CVE-2021-3944 is a medium-severity vulnerability in Bookstackapp Bookstack with a CVSS 3.x base score of 6.8. 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 6.8)
CVSS v2: 4.0
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-352
Affected product: Bookstackapp Bookstack
Published: 2021-12-02
Last modified: 2026-06-17

Description

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

Frequently asked questions

What is CVE-2021-3944?: bookstack is vulnerable to Cross-Site Request Forgery (CSRF)
How severe is CVE-2021-3944?: CVE-2021-3944 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-3944 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3944?: CVE-2021-3944 affects Bookstackapp Bookstack. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-3944?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-3944 published?: CVE-2021-3944 was published on 2021-12-02 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:bookstackapp:bookstack:*:*:*:*:*:*:*:*

More vulnerabilities in Bookstackapp Bookstack

CVE-2021-4119 — Critical (CVSS 9.8): bookstack is vulnerable to Improper Access Control
CVE-2020-5256 — High (CVSS 7.9): BookStack before version 0.25.5 has a vulnerability where a user could upload PHP files through image upload functions,…
CVE-2020-26211 — High (CVSS 7.7): In BookStack before version 0.30.4, a user with permissions to edit a page could insert JavaScript code through the use…
CVE-2020-26210 — High (CVSS 7.7): In BookStack before version 0.30.4, a user with permissions to edit a page could add an attached link which would…
CVE-2023-6199 — Medium (CVSS 6.5): Book Stack version 23.10.2 allows filtering local files on the server. This is possible because the application is…
CVE-2021-4194 — Medium (CVSS 6.5): bookstack is vulnerable to Improper Access Control

All CVEs affecting Bookstackapp Bookstack →

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 →