CVE-2026-44977 countly-server: Stored XSS in feedback upload enables app-admin to compromise global admin session context
A stored XSS vulnerability in Countly server allows app-admins to compromise global admin sessions by uploading malicious feedback files.
- 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-2026-44977?
CVE-2026-44977 is a critical cross-site scripting vulnerability in countly-server, published on 16 Oct 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
countly-server is the server-side part of Countly, a product analytics solution. Prior to 24.05.50 and 25.03.44, plugins/star-rating/api/api.js allows a non-global application administrator to use uploadFeedbackFile to store attacker-controlled active content while trusting the supplied MIME type. plugins/star-rating/frontend/app.js publicly serves the stored content from feedback/preview/ with the attacker-influenced Content-Type, so a global administrator who opens the preview executes the payload in the Countly origin and exposes authenticated session capabilities, including auth_token and csrf_token values. This issue is fixed in versions 24.05.50 and 25.03.44.
Weakness: CWE-79
Which versions are affected by CVE-2026-44977?
How do I fix CVE-2026-44977?
No fix has been published for CVE-2026-44977 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-2026-44977 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44977 exists.
Sources
Also known as GHSA-jqp4-p86c-phxc.