What’s Vulnerable › Vulnerabilities

CVE-2026-90583: kagisearch smallweb Query String Rendering sw.py index cross site scripting

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-13 · updated 2026-09-15
• Weakness: CWE-79

Description

A security flaw has been discovered in kagisearch smallweb up to 0ecb9c48edbf98dc7e934b54fbac43869e64b4cf. The affected element is the function index of the file app/sw.py of the component Query String Rendering. Performing a manipulation of the argument qs results in cross site scripting. The attack is possible to be carried out remotely. This product adopts a rolling release strategy to maintain continuous delivery. Therefore, version details for affected or updated releases cannot be specified. The patch is named 00b68144e583f20a6b67e29cf01bc07f57979ffb. It is recommended to apply a patch to fix this issue. Exploitability requires a raw HTTP request carrying unencoded double-quote characters in the query string - Werkzeug's request.query_string returns the raw request-target, and ordinary browsers percent-encode " as %22, so the payload only lands via netcat/curl-style raw sockets.

Affected products

• kagisearch smallweb: 0ecb9c48edbf98dc7e934b54fbac43869e64b4cf

References

• https://github.com/kagisearch/smallweb/
• https://github.com/kagisearch/smallweb/commit/00b68144e583f20a6b67e29cf01bc07f57979ffb
• https://github.com/kagisearch/smallweb/issues/854
• https://vuldb.com/cve/CVE-2026-90583
• https://vuldb.com/submit/913779
• https://vuldb.com/vuln/403168
• https://vuldb.com/vuln/403168/cti
• https://github.com/kagisearch/smallweb/issues/854

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