CVE-2026-86251 h3 before 1.15.9 Path Traversal via Double Decoding

h3 versions before 1.15.9 contain a path traversal vulnerability in the serveStatic utility. A double-decoding flaw allows a request path containing double-encoded dot sequences e.g. %252e%252e to be decoded to %2e%2e, which survives resolveDotSegments because that function only checks for litera...

CVE-2026-86251

Versions of h3 before 1.15.9 contain a path traversal vulnerability in the serveStatic utility. The root cause is a double-decoding flaw : a request path containing double-encoded dot sequences (e.g. %252e%252e) decodes to %2e%2e, which survives the resolveDotSegments() function because it only c...