What’s Vulnerable › Vulnerabilities

CVE-2026-44977: countly-server: Stored XSS in feedback upload enables app-admin to compromise global admin session context

• Severity: critical (CVSS 9.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-16 · updated 2026-10-21
• Weakness: CWE-79

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.

Affected products

• countly-server: before 24.05.50; from 25.03, < 25.03.44

References

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

Get alerted when CVE-2026-44977 or the next vulnerability affects your stack