---
id: CVE-2026-8023
title: >-
  Zephyr's HTTP server (subsys/net/lib/http) provides a static-filesystem
  resource type (HTTP_RESOURCE_TYPE_STATIC_FS, available when CONFIG_FILE_SYSTEM
  is enabled) that serves files from a configured root directory
summary: >-
  Zephyr's HTTP server (subsys/net/lib/http) provides a static-filesystem
  resource type (HTTP_RESOURCE_TYPE_STATIC_FS, available when CONFIG_FILE_SYSTEM
  is enabled) that serves files from a configured root directory. Before this
  fix, both …
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-22
  - CWE-23
  - CWE-22
vendor: zephyrproject
product: zephyr
affected:
  - 'zephyr >= 4.0.0, <= 4.4.1'
published: '2026-06-29'
updated: '2026-07-17'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-8023'
references:
  - url: >-
      https://github.com/zephyrproject-rtos/zephyr/commit/f4a423c98554f209c5d2f22f041822422c9263b8
    label: vulnerabilities@zephyrproject.org
  - url: >-
      https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-hch3-53g6-jj3h
    label: vulnerabilities@zephyrproject.org
  - url: >-
      https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-hch3-53g6-jj3h
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - exploit-available
epss: 0.0087
epssPercentile: 0.57296
ingestedAt: '2026-07-17T17:13:26.801Z'
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/ret2c/CVE-2026-8023'
  checkedAt: '2026-09-24T07:53:18.707Z'
exploitAvailable: true
---

## Overview

Zephyr's HTTP server (subsys/net/lib/http) provides a static-filesystem resource type (HTTP_RESOURCE_TYPE_STATIC_FS, available when CONFIG_FILE_SYSTEM is enabled) that serves files from a configured root directory. Before this fix, both the HTTP/1 and HTTP/2 front-ends placed the raw, attacker-controlled request path into client->url_buffer (assembled in on_url() for HTTP/1 and copied verbatim from the :path pseudo-header for HTTP/2) without resolving ./.. segments. The static-FS handler then built the on-disk filename by directly concatenating the configured root with that raw URL (snprintk(fname, ..., "%s%s", static_fs_detail->fs_path, client->url_buffer) at http_server_http1.c:603 and http_server_http2.c:490) and opened it with fs_open(fname, FS_O_READ). Because the handler is reached via wildcard/leading-dir (fnmatch FNM_LEADING_DIR) or fallback resource matching, a request such as GET /<prefix>/../../<file> is dispatched to the handler and, after the underlying filesystem (e.g. LittleFS/FAT) resolves the .. segments, escapes the configured web root, letting an unauthenticated remote client read arbitrary readable files on the mounted volume (information disclosure). The HTTP server requires no TLS or authentication to reach this path. The fix adds http_server_remove_dot_segments(), which canonicalizes the path portion of the URL before resource lookup in both protocol handlers, neutralizing the traversal. Affects releases v4.0.0 through v4.4.0 for deployments that register a static-filesystem resource.

## Affected

- `zephyr >= 4.0.0, <= 4.4.1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.