Vulnerability record · CVE-2026-25738 · published 19 February 2026
CVE-2026-25738: Cern indico toctou race condition vulnerability
Cern · Indico
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.
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.
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:
Affected products
1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
| Link | Tags |
|---|---|
| https://github.com/indico/indico/commit/70d341826116fac5868719a6133f2c26d9345137 | Patch |
| https://github.com/indico/indico/releases/tag/v3.3.10 | Release Notes |
| https://github.com/indico/indico/security/advisories/GHSA-f47c-3c5w-v7p4 | MitigationVendor Advisory |
Track CVE-2026-25738 inside VULONE
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Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-25738), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.
