CVE-2026-25738: Indico has Server-Side Request Forgery (SSRF) in multiple places
Impact Indico makes outgoing requests to user-provides URLs in various places. This is mostly intentional and part of Indico's functionality, but of course it is never intended to let you access "special" targets such as localhost or cloud metadata endpoints.
Patches You should to update to Indico 3.3.10 as soon as possible. See the docs for instructions on how to update.
Workarounds If you do not have IPs that expose sensitive data without authentication (typically because you do not host Indico on AWS), this vulnerability doesn't impact you and you can ignore it (but please upgrade anyway). Also, only event organizers can access endpoints where SSRF could be used to actually see the data returned by such a request. So if you trust your event organizers, the risk is also very limited.
For additional security, both before and after patching, you could also use the common proxy-related environment variables (in particular httpproxy and httpsproxy) to force outgoing requests to go through a proxy that limits requests in whatever way you deem useful/necessary. These environment variables would need to be set both on the indico-uwsgi and indico-celery services. Please note that setting up such a proxy is not something we can help you with.
For more information If you have any questions or comments about this advisory:
- Open a thread in our forum - Email us privately at indico-team@cern.ch
Other sources
Indico is an event management system that uses Flask-Multipass, a multi-backend authentication system for Flask. Versions prior to 3.3.10 are vulnerable to server-side request forgery. Indico makes outgoing requests to user-provides URLs in various places. This is mostly intentional and part of Indico's functionality but is never intended to let users access "special" targets such as localhost or cloud metadata endpoints. Users should upgrade to version 3.3.10 to receive a patch. Those who do not have IPs that expose sensitive data without authentication (typically because they do not host Indico on AWS) are not affected. Only event organizers can access endpoints where SSRF could be used to actually see the data returned by such a request. For those who trust their event organizers, the risk is also very limited. For additional security, both before and after patching, one may also use the common proxy-related environment variables (in particular httpproxy and httpsproxy) to force outgoing requests to go through a proxy that limits requests in whatever way you deem useful/necessary. These environment variables would need to be set both on the indico-uwsgi and indico-celery services.
— NVD
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-25738?
CVE-2026-25738 has been classified as a critical severity vulnerability due to its potential for SSRF exploitation.
How do I fix CVE-2026-25738?
To mitigate CVE-2026-25738, update Indico to version 3.3.10 or later.
What is the impact of CVE-2026-25738?
CVE-2026-25738 allows unauthorized access to internal services through Server-Side Request Forgery.
Which versions of Indico are affected by CVE-2026-25738?
Indico versions prior to 3.3.10 are vulnerable to CVE-2026-25738.
Is there a workaround for CVE-2026-25738 if I cannot upgrade?
Currently, there are no effective workarounds documented for CVE-2026-25738; upgrading is highly recommended.