CVE-2026-121562

Medium

Description

CTFd 3.1.0 before 3.8.7 contains an information disclosure vulnerability in the /api/v1/teams list endpoint that exposes non-public team custom field values. Unauthenticated attackers can paginate GET requests to collect hidden registration data such as emails, phone numbers, and student IDs when team mode and public visibility are enabled.

SeverityMedium

CVSS5.3

Exploit probability—

ProductCTFd

PublishedNov 3, 2026

First seenNov 4, 2026

Weakness typeCWE-863Incorrect authorization

How to fix

Update

CTFd CTFd3.8.7 or later

Patches

github.com/CTFd/CTFd/commit/122c224030224ca6a04d2928280055a84bbd4850

Vendor advisories

github.com/CTFd/CTFd/releases/tag/3.8.7

Affected products

Product	Affected versions	Fixed in
CTFd CTFd	3.1.0 ≤ v < 3.8.7	3.8.7

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.