Is CVE-2026-121562 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-121562 being exploited in the wild.

How severe is CVE-2026-121562?

Medium severity, with a CVSS score of 5.3, published 3 November 2026.

Is there a fix for CVE-2026-121562?

Yes: fixed in CTFd 3.8.7. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-121562 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-121562?

Check whether you run CTFd at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-121562: CTFd information disclosure in /api/v1/teams endpoint

CVE-2026-121562 · Severity: medium · CVSS 5.3 · Published 2026-11-03

CTFd is a platform for hosting and managing Capture The Flag (CTF) competitions. An information disclosure vulnerability in versions before 3.8.7 allows unauthenticated attackers to retrieve hidden team custom field values—such as emails, phone numbers, and student IDs—through the /api/v1/teams API endpoint when team mode and public visibility are enabled. This exposes sensitive registration data that was intended to be private.

Technologies: CTFd. Vendors: CTFd.

Quick answers

Is CVE-2026-121562 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-121562 being exploited in the wild.
How severe is CVE-2026-121562?: Medium severity, with a CVSS score of 5.3, published 3 November 2026.
Which products and versions are affected?: CTFd 3.1.0 before 3.8.7.
Is there a fix for CVE-2026-121562?: Yes: fixed in CTFd 3.8.7. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-121562 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-121562?: Check whether you run CTFd at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: CTFd 3.8.7

Technical details

The REST API endpoint /api/v1/teams fails to enforce visibility controls for custom fields, returning field values regardless of their public/private designation. An unauthenticated attacker can enumerate teams using pagination on GET requests to collect all exposed custom field data. The vulnerability is present in CTFd 3.1.0 through 3.8.6 and requires team mode and public visibility to be enabled, but no authentication or user interaction.

Affected products

CTFd CTFd 3.1.0 before 3.8.7

Timeline

2026-11-03: disclosed
2026-08-19: patched: v3.8.7 released with fix

References

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