by Kastro
Paper/Archive/CVE-2026-44977

CVE-2026-44977

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

EPSS 0.4%public exploitCVSS 9.0
critical.is priorityof 100
45
CVSS 9.0 (CNA)9.0 / 10 × 3027.0Not in CISA KEV+300.0EPSS percentile 37.8.378 × 207.6Exploit: SSVC poc+1010.0SSVC exploitation: poc+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
countly-server< 24.05.50–CNA
countly-server>= 25.03, < 25.03.44–CNA

Scores by source

GitHub_M (CNA)9.0CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: total

References

exploitgithub.com/Countly/countly-server/security/advisories/GHSA-jqp4-p86c-phxcrefgithub.com/Countly/countly-server/commit/ae899f37bc6d70c1b44859756ce80a204ae72631refgithub.com/Countly/countly-server/commit/fcb16c808c0fdb6dc99fe9c66de7fc560b3a9c41refgithub.com/Countly/countly-server/releases/tag/24.05.50refgithub.com/Countly/countly-server/releases/tag/25.03.44