CVE-2026-121562: CTFd CTFd

CTFd 3.1.0 before 3.8.7 Information Disclosure via /api/v1/teams Endpoint

CVSS 6.9 MediumEPSS 0.0033 · 25th percentile

Published by the CVE Program (CNA: VulnCheck) at 3 Nov 2026, 15:17 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
CTFd	CTFd	affected 3.1.0 to before 3.8.7 semver Other versions: unaffected

Identifiers

CVE-2026-121562

CNA

VulnCheck

Weakness (CWE)

CWE-863

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
6.9	Medium	4.0	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N	CNA (VulnCheck)Used for this record
5.3	Medium	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N	CNA (VulnCheck)

CISA KEV Not listed.
EPSS 0.0033, the 25th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

3 Nov 2026, 15:17 UTC Confirmed by the CVE List
3 Nov 2026, 15:23 UTC First seen by agentprime
3 Nov 2026, 16:17 UTC Confirmed by NVD

Sources

References from the CNA

github.com/CTFd/CTFd/commit/122c224030224ca6a04d2928280055a84bbd4850 patch
github.com/CTFd/CTFd product
github.com/CTFd/CTFd/blob/3.8.6/CTFd/api/v1/teams.py#L128-L131 technical-description
github.com/CTFd/CTFd/blob/3.8.6/CTFd/schemas/teams.py#L336-L363 technical-description
blog.ctfd.io/ctfd-3-8-7/ technical-description
github.com/CTFd/CTFd/releases/tag/3.8.7 technical-descriptionrelease-notes
www.vulncheck.com/advisories/ctfd-3.1.0-before-3.8.7-information-disclosure-via-api-v1-teams-endpoint third-party-advisory

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.