CVE-2026-39940
CVE-2026-39940 is a medium-severity vulnerability with a CVSS 4.0 base score of 5.3. 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-601.
Key facts
- Severity: Medium (CVSS 4.0 base score 5.3)
- EPSS exploit prediction: 0% (19th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-22011
- Weakness: CWE-601
- Published:
- Last modified:
Description
ChurchCRM is an open-source church management system. Prior to 7.0.0, it was possible in many places across the ChurchCRM application to create a link that, when visited by an authenticated user, would redirect them to any URL chosen by an attacker if they clicked 'Cancel' button on the page. For this write-up the DonatedItemEditor.php will be used as an example, however wherever all instances of 'linkBack' should be assessed. This vulnerability is fixed in 7.0.0.
Frequently asked questions
- What is CVE-2026-39940?
- ChurchCRM is an open-source church management system. Prior to 7.0.0, it was possible in many places across the ChurchCRM application to create a link that, when visited by an authenticated user, would redirect them to any URL chosen by an attacker if they clicked 'Cancel' button on the page. For this write-up the DonatedItemEditor.php will be used as an example, however wherever all instances of 'linkBack' should be assessed. This vulnerability is fixed in 7.0.0.
- How severe is CVE-2026-39940?
- CVE-2026-39940 has a CVSS 4.0 base score of 5.3, rated medium severity.
- Is CVE-2026-39940 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-39940?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-39940 have an EU (EUVD) identifier?
- Yes. CVE-2026-39940 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-22011.
- When was CVE-2026-39940 published?
- CVE-2026-39940 was published on 2026-04-13 and last updated on 2026-06-17.
References
- https://github.com/ChurchCRM/CRM/security/advisories/GHSA-5g52-rvjf-6wwf
- https://github.com/ChurchCRM/CRM/security/advisories/GHSA-v3hj-33xf-qx47
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