What is CVE-2025-53640?

CVE-2025-53640 is a medium-severity vulnerability in Cern Indico, classified under Information Disclosure. CVSS score: 6.5/10. Published 2025-07-14.

How severe is CVE-2025-53640?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Is CVE-2025-53640 known to be exploited?

3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Auth bypass in Cern Indico

CVE-2025-53640

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.

Vulnerability class: Information Disclosure

Published 2025-07-14 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.006 (46.8th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: +0.000

Affected products

Cern Indico
Indico — versions >= 2.2, < 3.3.7

Weakness classification (CWE)

Public proof-of-concept exploits

References

github.com/indico/indico/security/advisories/GHSA-q28v-664f-q6wj (Vendor Advisory)
docs.getindico.io/en/stable/config/settings/ (Product)
docs.getindico.io/en/stable/installation/upgrade (Product)
github.com/indico/indico/releases/tag/v3.3.7 (Release Notes)
af854a3a-2127-422b-91ae-364da2661108 (Exploit, Third Party Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Exploit, Mitigation, Third Party Advisory)

Frequently asked questions

What is CVE-2025-53640?: CVE-2025-53640 is a medium-severity vulnerability in Cern Indico, classified under Information Disclosure. CVSS score: 6.5/10. Published 2025-07-14.
How severe is CVE-2025-53640?: Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2025-53640 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.