# CVE-2026-103491: JetBrains YouTrack insecure direct object reference in issue activities API

Source: https://junglewise.ai/threats/cve-2026-103491-in-jetbrains-youtrack-before-2026-2-19422-idor-in-the-issue  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-01. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-103491 · Severity: medium · CVSS 6.5 · Published 2026-10-01

YouTrack is a project tracking and issue management system used by development teams to organize work. An insecure direct object reference flaw in the issue activities API allows attackers to read restricted issues they should not have access to, potentially exposing sensitive project information and business details.

Technologies: [Jetbrains YouTrack](https://junglewise.ai/threats/technologies/youtrack). Vendors: [Jetbrains](https://junglewise.ai/threats/vendors/jetbrains).

## Quick answers

**Is CVE-2026-103491 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-103491 being exploited in the wild.

**How severe is CVE-2026-103491?** Medium severity, with a CVSS score of 6.5, published 1 October 2026.

**Which products and versions are affected?** Jetbrains YouTrack before 2026.2.19422.

**Is there a fix for CVE-2026-103491?** Yes: fixed in YouTrack 2026.2.19422. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-103491 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-103491?** Check whether you run Jetbrains YouTrack 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 YouTrack 2026.2.19422

## Technical details

The issue activities API in YouTrack contains an IDOR vulnerability that fails to properly validate access controls when retrieving issue activity data. An attacker with network access can enumerate and read restricted issues by directly accessing the API with modified object identifiers, bypassing intended authorization checks. A fix is available in version 2026.2.19422 and later.

## Affected products

- JetBrains YouTrack before 2026.2.19422

## Timeline

- 2026-10-01: disclosed

## References

- [https://www.jetbrains.com/privacy-security/issues-fixed/](https://www.jetbrains.com/privacy-security/issues-fixed/)

## Related threats

- [JetBrains YouTrack missing authorization in VCS hosting configuration](https://junglewise.ai/threats/cve-2026-123332-in-jetbrains-youtrack-before-2026-2-19562-missing-authorization)
- [JetBrains YouTrack article visibility restriction bypass](https://junglewise.ai/threats/cve-2026-123331-in-jetbrains-youtrack-before-2026-2-19197-article-editors-could)
- [JetBrains YouTrack missing authorization in issue visibility settings](https://junglewise.ai/threats/cve-2026-123330-in-jetbrains-youtrack-before-2026-2-19562-missing-authorization)
- [JetBrains YouTrack missing authorization in TeamCity integration](https://junglewise.ai/threats/cve-2026-123329-in-jetbrains-youtrack-before-2026-2-19562-missing-authorization)
- [JetBrains YouTrack app permission bypass privilege escalation](https://junglewise.ai/threats/cve-2026-123328-in-jetbrains-youtrack-before-2026-2-19656-app-permission-bypass)