Vulnerability · Published Aug 23, 2026 · Assigned by VulDB
CVE-2026-78145CTFd __init__.py _is_safe_url redirect
Medium 4.3
In plain English
A medium-severity open redirect in CTFd. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 47% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
Weakness: CWE-601 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C
References
- VDB-394533 | CTFd __init__.py _is_safe_url redirect vdb-entry, technical-description
- VDB-394533 | CTI Indicators (IOB, IOC, TTP, IOA) signature, permissions-required
- CVE-2026-78145 | CVE Analysis and Report third-party-advisory
- Submit #882469 | CTFd https://github.com/CTFd/CTFd v3.8.4 Open Redirect third-party-advisory
- https://mblunt.dev/writeups/ctfd-open-redirect/ exploit
- https://github.com/CTFd/CTFd/pull/3026 issue-tracking, patch
- https://github.com/CTFd/CTFd/commit/5d8515842fd1ab2c3a9f2dde9ffca907aa334ea9 patch
- https://github.com/CTFd/CTFd/releases/tag/3.8.4 patch
- https://github.com/CTFd/CTFd/ product