Countly countly-server up to 24.05.49/25.03.43 Local File System Storage /images/screenshots getStream improper synchronization

Summaryinfo

A vulnerability has been found in Countly countly-server up to 24.05.49/25.03.43 and classified as problematic. Affected by this vulnerability is the function getStream of the file /images/screenshots of the component Local File System Storage. This manipulation causes improper synchronization. This vulnerability appears as CVE-2026-42270. The attack may be initiated remotely. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Countly countly-server up to 24.05.49/25.03.43. It has been declared as problematic. Affected by this vulnerability is the function getStream of the file /images/screenshots of the component Local File System Storage. The manipulation with an unknown input leads to a improper synchronization vulnerability. The CWE definition for the vulnerability is CWE-662. The product utilizes multiple threads or processes to allow temporary access to a shared resource that can only be exclusive to one process at a time, but it does not properly synchronize these actions, which might cause simultaneous accesses of this resource by multiple threads or processes. As an impact it is known to affect availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-42270 since 04/26/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available.

Upgrading to version 24.05.50 or 25.03.44 eliminates this vulnerability.

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Productinfo

Vendor

• Countly

Name

• countly-server

Version

• 24.05.0
• 24.05.1
• 24.05.2
• 24.05.3
• 24.05.4
• 24.05.5
• 24.05.6
• 24.05.7
• 24.05.8
• 24.05.9
• 24.05.10
• 24.05.11
• 24.05.12
• 24.05.13
• 24.05.14
• 24.05.15
• 24.05.16
• 24.05.17
• 24.05.18
• 24.05.19
• 24.05.20
• 24.05.21
• 24.05.22
• 24.05.23
• 24.05.24
• 24.05.25
• 24.05.26
• 24.05.27
• 24.05.28
• 24.05.29
• 24.05.30
• 24.05.31
• 24.05.32
• 24.05.33
• 24.05.34
• 24.05.35
• 24.05.36
• 24.05.37
• 24.05.38
• 24.05.39
• 24.05.40
• 24.05.41
• 24.05.42
• 24.05.43
• 24.05.44
• 24.05.45
• 24.05.46
• 24.05.47
• 24.05.48
• 24.05.49
• 25.03.0
• 25.03.1
• 25.03.2
• 25.03.3
• 25.03.4
• 25.03.5
• 25.03.6
• 25.03.7
• 25.03.8
• 25.03.9
• 25.03.10
• 25.03.11
• 25.03.12
• 25.03.13
• 25.03.14
• 25.03.15
• 25.03.16
• 25.03.17
• 25.03.18
• 25.03.19
• 25.03.20
• 25.03.21
• 25.03.22
• 25.03.23
• 25.03.24
• 25.03.25
• 25.03.26
• 25.03.27
• 25.03.28
• 25.03.29
• 25.03.30
• 25.03.31
• 25.03.32
• 25.03.33
• 25.03.34
• 25.03.35
• 25.03.36
• 25.03.37
• 25.03.38
• 25.03.39
• 25.03.40
• 25.03.41
• 25.03.42
• 25.03.43

Website

• Product: https://github.com/Countly/countly-server/

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Entryinfo

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