Quick answers
- Is CVE-2026-40541 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-40541 being exploited in the wild.
- How severe is CVE-2026-40541?
- Critical severity, with a CVSS score of 9, published 28 August 2026.
- Which products and versions are affected?
- Synology Chat Server before 2.4.5-22148.
- Is there a fix for CVE-2026-40541?
- A patch was published on 2026-05-26: Fix available in version 2.4.5-22148 or later Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-40541 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-40541?
- Check whether you run Synology Chat Server 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.
Technical details
CVE-2026-40541 is an improper input neutralization vulnerability (CWE-79) in the domain extraction functionality of Synology Chat Server versions before 2.4.5-22148. The vulnerability requires authentication and user interaction (clicking malicious links or content). An authenticated attacker can inject arbitrary JavaScript that executes with the privileges of the victim's session in a DSM context, allowing them to read/write arbitrary files and conduct denial-of-service attacks. The fix is available in Synology Chat Server 2.4.5-22148 and later.
Affected products
- Synology Chat Server before 2.4.5-22148
Timeline
- 2026-05-26: disclosed
- 2026-05-26: patched: Fix available in version 2.4.5-22148 or later