CVE-2025-53640 — indico
CVE-2025-53640 is a Information Exposure vulnerability in indico. A fix is available for indico — see the affected versions and patch details below.
Indico vulnerable to user enumeration via API endpoint
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-53640.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
indicoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Indico is an event management system that uses Flask-Multipass, a multi-backend authentication system for Flask. Starting in version 2.2 and prior to version 3.3.7, an endpoint used to display details of users listed in certain fields (such as ACLs) could be misused to dump basic user details (such as name, affiliation and email) in bulk. Version 3.3.7 fixes the issue. Owners of instances that allow everyone to create a user account, who wish to truly restrict access to these user details, should consider restricting user search to managers. As a workaround, it is possible to restrict access to the affected endpoints (e.g. in the webserver config), but doing so would break certain form fields which could no longer show the details of the users listed in those fields, so upgrading instead is highly recommended.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | indico | ≥ 2.2&&< 3.3.7 | 3.3.7pip install --upgrade 'indico==3.3.7' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for indico, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update indico to 3.3.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-53640 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-53640 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-53640. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-53640 in your dependencies?
O3 Security finds CVE-2025-53640 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.