What is CVE-2026-109937?

CVE-2026-109937 is a medium-severity vulnerability in Otter Blocks, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 5.4/10. Published 2026-10-18.

How severe is CVE-2026-109937?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Open Redirect in Otter Blocks

CVE-2026-109937

The Otter Blocks WordPress plugin before 3.2.3 does not validate that a user-supplied return URL belongs to the site before using it to build the return destination of a Stripe Checkout session, allowing unauthenticated attackers to redirect victims who complete or cancel checkout to an arbitrary external URL.

Vulnerability class: Open Redirect

Published 2026-10-18 · last modified 2026-10-18.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Otter Blocks

Weakness classification (CWE)

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

References

wpscan.com/vulnerability/9765313d-c879-457f-851f-dab74b8d90a0/ (technical-description, exploit, vdb-entry)

Frequently asked questions

What is CVE-2026-109937?: CVE-2026-109937 is a medium-severity vulnerability in Otter Blocks, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 5.4/10. Published 2026-10-18.
How severe is CVE-2026-109937?: Medium severity. CVSS v3 base score is 5.4 out of 10.