A vulnerability has been found in CTFd up to 3.8.4. The affected element is the function _is_safe_url of the file CTFd/utils/validators/__init__.py. Such manipulation of the argument Next leads to open redirect. The attack can be launched remotely. The exploit has been disclosed to the public and may be used. The name of the patch is 5d8515842fd1ab2c3a9f2dde9ffca907aa334ea9. Upgrading the affected component is recommended.
https://vuldb.com/vuln/394533/cti
https://vuldb.com/submit/882469
https://vuldb.com/cve/CVE-2026-78145
https://mblunt.dev/writeups/ctfd-open-redirect/
https://github.com/CTFd/CTFd/releases/tag/3.8.4
https://github.com/CTFd/CTFd/pull/3026
https://github.com/CTFd/CTFd/commit/5d8515842fd1ab2c3a9f2dde9ffca907aa334ea9
Published: 2026-08-23
Updated: 2026-08-23
Base Score: 5
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N
Severity: Medium
Base Score: 4.3
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
Severity: Medium
Base Score: 5.3
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Severity: Medium