Quick answers
- Is CVE-2026-115574 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-115574 being exploited in the wild.
- How severe is CVE-2026-115574?
- Medium severity, with a CVSS score of 5.3, published 4 November 2026.
- Which products and versions are affected?
- Zulip 11.0 to 12.1.
- Is there a fix for CVE-2026-115574?
- Yes: fixed in 12.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-115574 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-115574?
- Check whether you run Zulip at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 12.2
Technical details
The GET /json/users endpoint was accessible to spectators (logged-out users) on realms with web-public channels enabled. The endpoint honored the include_custom_profile_fields parameter without enforcing access control, allowing unauthenticated visitors to retrieve custom profile field values for all users. The fix adds a check in get_users_for_api() to ensure spectators (denoted by acting_user=None) cannot request custom profile fields, regardless of the parameter value.
Affected products
- Zulip Zulip 11.0 to 12.1
Timeline
- 2026-11-04: disclosed