CVE-2026-86251

The record

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

Related vulnerabilities

• CVE-2026-81163 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')… CWE-22
• CVE-2026-112049 Vita3K before build 4187 contains a path traversal (zip slip) vulnerability in… CWE-22
• CVE-2026-112005 WhoDB 0.104.0 before 0.135.0 contains a path traversal vulnerability that allows remote… CWE-22
• CVE-2026-61702 OpenPrinting CUPS is an open source printing system for Linux and other Unix-like… CWE-22
• CVE-2026-104871 The Angular SSR is a server-rise rendering tool for Angular applications. CWE-22
• CVE-2026-102991 Mako is a template library written in Python. CWE-22
• CVE-2026-101894 The decompress package for Node.js extracts archives. CWE-22
• CVE-2026-100689 GitPython before 3.1.62 does not validate the `path` field read from an untrusted… CWE-22