Answer in brief
CVE-2026-86253 records a High severity (CVSS 5.9) vulnerability in h3 before 1.15.6 Path Traversal via Percent-Encoded Dot Segments. The current sources do not mark it as known exploited. The current feed maps h3js/h3 (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps h3js/h3 (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| h3js/h3generic | >=0 <1.15.6 || >=2.0.0-beta.0 <2.0.1-rc.15 | 1.15.6, 2.0.1-rc.15 |
Published upstream
Sep 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 6, 2026
h3 (npm package) versions <= 2.0.1-rc.14 contain a path traversal vulnerability in serveStatic(). On Node.js deployments, event.url.pathname is not normalized, so percent-encoded dot segments (%2e%2e) are passed to decodeURI() and decoded to ../ sequences without sanitization. An unauthenticated remote attacker can send crafted requests to endpoints served by serveStatic() to read arbitrary files outside the intended static directory. Fixed in 1.15.6 and 2.0.1-rc.15.
Quoted source text, attributed separately from HOL analysis.