CVE-2026-78145: Open Redirect in CTFd
Description
CVE-2026-78145 is an open redirect vulnerability in CTFd versions 3.8.0 through 3.8.4. It arises from improper validation in the _is_safe_url function in CTFd/utils/validators/__init__.py, allowing manipulation of the Next parameter to redirect users to arbitrary URLs. The vulnerability can be exploited remotely and requires user interaction. A patch has been identified and upgrading is recommended to mitigate the issue.
CVSS v4.0
Score 5.3medium
Affected software
CTFd
pkg:github/ctfd/CTFdcpe:2.3:a:ctfd:ctfd:*:*:*:*:*:*:*:*Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-78145 affects CTFd versions 3.8.0 to 3.8.4 due to insufficient validation in the _is_safe_url function located in CTFd/utils/validators/__init__.py. This flaw allows attackers to manipulate the Next parameter to perform an open redirect, potentially redirecting users to malicious sites. The vulnerability is remotely exploitable without privileges and requires user interaction. A patch identified by commit 5d8515842fd1ab2c3a9f2dde9ffca907aa334ea9 is available, and upgrading to a fixed version is advised.
Potential Impact
Successful exploitation of this vulnerability allows an attacker to redirect users to arbitrary external URLs, which can be used in phishing attacks or to deliver malicious content. The vulnerability does not require authentication and can be triggered remotely, but it requires user interaction to follow the malicious redirect. The CVSS 4.0 base score is 5.3, indicating a medium severity impact.
Mitigation Recommendations
A patch has been identified for this vulnerability (commit 5d8515842fd1ab2c3a9f2dde9ffca907aa334ea9). Users of CTFd versions 3.8.0 through 3.8.4 should upgrade to a fixed version that includes this patch to remediate the open redirect issue. No additional vendor advisory was provided, so check the official CTFd repository or release notes for the exact fixed version and upgrade instructions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulDB
- Date Reserved
- 2026-08-23T06:27:57.055Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a8b80d0acd9273b4982ddba
Added to database: 08/23/2026, 23:22:56 UTC
Last enriched: 09/10/2026, 23:18:07 UTC
Last updated: 10/07/2026, 18:48:23 UTC
Views: 87
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