SeaweedFS up to 4.29 JSON Endpoint weed/server/common.go cross site scripting

Summaryinfo

A vulnerability categorized as problematic has been discovered in SeaweedFS up to 4.29. This impacts an unknown function of the file weed/server/common.go of the component JSON Endpoint. Such manipulation leads to cross site scripting. This vulnerability is referenced as CVE-2026-58371. It is possible to launch the attack remotely. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in SeaweedFS up to 4.29 and classified as problematic. Affected by this issue is an unknown functionality of the file weed/server/common.go of the component JSON Endpoint. The manipulation with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Impacted is integrity. CVE summarizes:

SeaweedFS before 4.30 reflects the callback query parameter verbatim into responses served with Content-Type application/javascript in the shared writeJson helper (weed/server/common.go), with no callback-name validation, no X-Content-Type-Options: nosniff header, and no CORS allow-list. Every JSON endpoint that uses writeJson - including the unauthenticated master endpoints /dir/status, /dir/lookup and /cluster/status, the volume server /status, and the filer directory listing, all reachable in the default configuration (no -whiteList, no security.toml, bound to 0.0.0.0) - can therefore be loaded cross-origin via a script tag with a chosen callback, letting a third-party web page read cluster topology, volume server URLs and gRPC ports, file identifiers, and directory listings. Because the callback string is reflected at the start of the body and no nosniff header is sent, MIME-sniffing clients may also interpret the reflected content as HTML.

The weakness was published by George Chen. The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-58371 since 06/30/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 4.30 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 77dcb20a7485074d37340985d53103f94538abe6 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

• SeaweedFS

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14
• 4.15
• 4.16
• 4.17
• 4.18
• 4.19
• 4.20
• 4.21
• 4.22
• 4.23
• 4.24
• 4.25
• 4.26
• 4.27
• 4.28
• 4.29

License

• open-source

Website

• Product: https://github.com/seaweedfs/seaweedfs/

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