CVE-2026-44977countly-server: Stored XSS in feedback upload enables app-admin to compromise global admin session context
- 9.0CriticalCVSS base score
- 0.44%Exploitation in 30 daysEPSS · top 62% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
- https://github.com/Countly/countly-server/security/advisories/GHSA-jqp4-p86c-phxc (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 5 months later
· 5 months later
Published
- 5 days later
· 5 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Critical9.0 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H |
| NVDNVD · Awaiting Analysis | 3.1 | Critical9.0 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.44% · top 62% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.0.
Affected products
- affected < 24.05.50
- affected >= 25.03, < 25.03.44
References
References5
- https://github.com/Countly/countly-server/security/advisories/GHSA-jqp4-p86c-phxc (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/Countly/countly-server/commit/ae899f37bc6d70c1b44859756ce80a204ae72631 (opens in a new tab)x_refsource_MISC
- https://github.com/Countly/countly-server/commit/fcb16c808c0fdb6dc99fe9c66de7fc560b3a9c41 (opens in a new tab)x_refsource_MISC
- https://github.com/Countly/countly-server/releases/tag/24.05.50 (opens in a new tab)x_refsource_MISC
- https://github.com/Countly/countly-server/releases/tag/25.03.44 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-102918 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-44977)Record last updated .