CVE-2026-86253

    Dashboard / Vulnerabilities / CVE-2026-86253

    CVE-2026-86253

    Published: 6 Sept 2026Last Modified: 12 Sept 2026

    Summary: h3 before 1.15.6 Path Traversal via Percent-Encoded Dot Segments

    Details: 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.

    References: https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86253.json, https://github.com/h3js/h3/security/advisories/GHSA-wr4h-v87w-p3r7, https://nvd.nist.gov/vuln/detail/CVE-2026-86253, https://www.vulncheck.com/advisories/h3-before-1.15.6-path-traversal-via-percent-encoded-dot-segments

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -829daf157e5add61d60fb18dfdd9f6885e57a5e3

    Affected versions

    v1.15.5
    v1.15.4
    v1.15.2
    v1.15.1
    v1.15.0

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2026-86253 | CVE-DB