CVE-2026-86251
h3 versions before 1.15.9 contain a path traversal vulnerability in the serveStatic utility.
Impact
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 literal '.' characters. When the resulting asset ID is resolved by URL-based backends (CDN, S3, object storage), %2e%2e is interpreted as '..' per RFC 3986, enabling path traversal to read arbitrary files from the backend.
Affected packages
This record carries no package version data, so it cannot be matched against a dependency list automatically. Read the advisory and compare your version by hand.