CVE-2026-25738: Indico is an event management system that uses Flask-Multipass, a multi-backend authentication system for Flask. Versions prior to 3.3.10 are vulnerab...

Description

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 `http_proxy` and `https_proxy`) 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.

Metrics

CVSS 3.1

4.3/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CVSS 4.0

6.9/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.19%

8.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cern	Indico	< 3.3.10

References

https://github.com/indico/indico/commit/70d341826116fac5868719a6133f2c26d9345137Patch
https://github.com/indico/indico/releases/tag/v3.3.10Release Notes
https://github.com/indico/indico/security/advisories/GHSA-f47c-3c5w-v7p4Mitigation, Vendor Advisory

Timeline

Published: Feb 19, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-25738?

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 `http_proxy` and `https_proxy`) 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.

How severe is CVE-2026-25738?

CVE-2026-25738 has a CVSS score of 6.9/10 (MEDIUM severity). The EPSS model estimates a 0.19% probability of exploitation in the next 30 days.

How do I fix CVE-2026-25738?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.