Open Redirect Vulnerability in CTFd by CTFd Development Team
CVE-2026-78145

5.3MEDIUM

Key Information:

Vendor

CTFd Development Team

Status
Ctfd
Vendor
CVE Published:
23 August 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-78145?

A security flaw has been identified in CTFd versions up to 3.8.4, specifically within the _is_safe_url function located in CTFd/utils/validators/init.py. This vulnerability allows an attacker to manipulate the 'Next' parameter, leading to an open redirect issue. Exploitation can be performed remotely, making it crucial for users to update their installations. A patch has been released to address this issue; upgrading to the latest version is highly recommended to mitigate potential security risks.

Affected Version(s)

CTFd 3.8.0

CTFd 3.8.1

CTFd 3.8.2

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-78145 - Proof of Concept

References

https://vuldb.com/vuln/394533
vdb-entrytechnical-description
https://vuldb.com/vuln/394533/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-78145
third-party-advisory

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

mblunt (VulDB User)
.