CVE-2026-44977

CRITICAL 9.0

countly-server: Stored XSS in feedback upload enables app-admin to compromise global admin session context

CVSS Score

9.0

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-79
Vendor	countly
Product	countly-server
Published	Oct 16, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

Countly / countly-server

< 24.05.50 >= 25.03, < 25.03.44

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/Countly/countly-server/security/advisories/GHSA-jqp4-p86c-phxc github.com: https://github.com/Countly/countly-server/commit/ae899f37bc6d70c1b44859756ce80a204ae72631 github.com: https://github.com/Countly/countly-server/commit/fcb16c808c0fdb6dc99fe9c66de7fc560b3a9c41 github.com: https://github.com/Countly/countly-server/releases/tag/24.05.50 github.com: https://github.com/Countly/countly-server/releases/tag/25.03.44