What is CVE-2026-42270?

CVE-2026-42270 is a high-severity vulnerability in Countly Countly-Server, classified under CWE-248. CVSS score: 7.5/10. Published 2026-10-16.

How severe is CVE-2026-42270?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Countly Countly-Server

CVE-2026-42270

countly-server is the server-side part of Countly, a product analytics solution. Prior to 24.05.50 and 25.03.44, star-rating/images/ and dashboards/images/screenshots/ are among public image and screenshot routes using the local fs storage backend that call getStream and pipe filesystem streams to HTTP responses without an error listener. An unauthenticated request containing a URL-encoded dot can make createReadStream open a directory, emit an asynchronous EISDIR error, and terminate the Node.js process as an unhandled exception, allowing repeated requests to keep the analytics API unavailable. The affected routes also include /appimages/*, /memberimages/*, and */screenshots/*. This issue is fixed in versions 24.05.50 and 25.03.44.

Published 2026-10-16 · last modified 2026-10-16.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Countly Countly-Server — versions < 24.05.50, >= 25.03, < 25.03.44

Weakness classification (CWE)

CWE-248

References

Frequently asked questions

What is CVE-2026-42270?: CVE-2026-42270 is a high-severity vulnerability in Countly Countly-Server, classified under CWE-248. CVSS score: 7.5/10. Published 2026-10-16.
How severe is CVE-2026-42270?: High severity. CVSS v3 base score is 7.5 out of 10.