CVE-2026-44977: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in Countly countly-server
Description
CVE-2026-44977 is a critical cross-site scripting (XSS) vulnerability in the countly-server component of Countly, a product analytics solution. The flaw exists in the star-rating plugin's API and frontend, where a non-global application administrator can upload attacker-controlled active content with a trusted MIME type. This content is then served with the attacker-influenced Content-Type to global administrators, allowing execution of malicious payloads in the Countly origin. This can expose authenticated session tokens such as auth_token and csrf_token. The vulnerability is fixed in versions 24.05.50 and 25.03.44.
CVSS v3.1
Score 9.0critical
Affected software
Countly
countly-server
pkg:github/countly/countly-serverRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in countly-server arises from improper neutralization of input during web page generation (CWE-79). Specifically, the star-rating plugin's API (plugins/star-rating/api/api.js) allows a non-global admin to upload feedback files containing active content with a MIME type that is trusted without validation. The frontend (plugins/star-rating/frontend/app.js) then serves this content from feedback/preview/ with the attacker-controlled Content-Type header. When a global administrator previews this content, the malicious payload executes within the Countly origin, potentially exposing sensitive session tokens including auth_token and csrf_token. This issue is resolved in versions 24.05.50 and 25.03.44.
Potential Impact
Successful exploitation allows an attacker with non-global admin privileges to execute arbitrary scripts in the context of a global administrator's browser session. This leads to exposure of sensitive authentication tokens (auth_token and csrf_token), enabling session hijacking and potentially full compromise of the global administrator's account. The vulnerability has a CVSS 3.1 score of 9.0 (critical), reflecting its high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
Upgrade countly-server to version 24.05.50 or later, or 25.03.44 or later, where this vulnerability is fixed. No other mitigations are indicated by the vendor advisory. Patch status is confirmed fixed in these versions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-08T16:23:33.264Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ad24ee02cdf04f65608e186
Added to database: 10/16/2026, 16:20:48 UTC
Last enriched: 10/16/2026, 16:33:16 UTC
Last updated: 10/16/2026, 16:35:31 UTC
Views: 6
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