CVE-2026-9548 Cross-site scripting in Synology Chat Server
Remote authenticated users can exploit Cross-site Scripting in Synology Chat Server to read or write restricted files and cause limited denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-9548?
CVE-2026-9548 is a medium-severity cross-site scripting vulnerability in Synology Chat Server, published on 28 Aug 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
An improper neutralization of input during web page generation ('Cross-site Scripting') vulnerability in extract domain in Synology Chat Server before 2.4.5-22148 allows remote authenticated users, via a UI interaction, to read or write restricted files and conduct limited denial-of-service attacks in DSM.
Weakness: CWE-79
Which versions are affected by CVE-2026-9548?
How do I fix CVE-2026-9548?
No fix has been published for CVE-2026-9548 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-9548 being exploited?
There is no known exploitation of CVE-2026-9548 in the wild and no public exploit code.
Sources
Also known as GHSA-6788-84vh-frqm.