How severe is CVE-2026-4160?

CVE-2026-4160 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2026-4160 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-4160?

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

Does CVE-2026-4160 have an EU (EUVD) identifier?

Yes. CVE-2026-4160 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23237.

When was CVE-2026-4160 published?

CVE-2026-4160 was published on 2026-04-16 and last updated on 2026-06-17.

CVE-2026-4160

CVE-2026-4160 is a medium-severity vulnerability with a CVSS 3.x 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-639.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-23237
Weakness: CWE-639
Published: 2026-04-16
Last modified: 2026-06-17

Description

The Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder plugin for WordPress is vulnerable to Insecure Direct Object Reference via the 'submission_id' parameter in versions up to, and including, 6.1.21. This is due to missing authorization and ownership validation on a user controlled key in the Stripe SCA confirmation AJAX endpoint. This makes it possible for unauthenticated attackers to modify payment status of targeted pending submissions (for example, setting the status to "failed").

Frequently asked questions

What is CVE-2026-4160?: The Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder plugin for WordPress is vulnerable to Insecure Direct Object Reference via the 'submission_id' parameter in versions up to, and including, 6.1.21. This is due to missing authorization and ownership validation on a user controlled key in the Stripe SCA confirmation AJAX endpoint. This makes it possible for unauthenticated attackers to modify payment status of targeted pending submissions (for example, setting the status to "failed").
How severe is CVE-2026-4160?: CVE-2026-4160 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2026-4160 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-4160?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-4160 have an EU (EUVD) identifier?: Yes. CVE-2026-4160 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23237.
When was CVE-2026-4160 published?: CVE-2026-4160 was published on 2026-04-16 and last updated on 2026-06-17.

References

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