CVE-2026-8023
Path traversal in Zephyr HTTP server static-filesystem resource handler allows unauthenticated remote arbitrary file read
Description
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.
INFO
Published Date :
June 29, 2026, 10:15 p.m.
Last Modified :
June 29, 2026, 10:15 p.m.
Remotely Exploit :
No
Source :
zephyr
Affected Products
The following products are affected by CVE-2026-8023
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | e2e69745-5e70-4e92-8431-deb5529a81ad |
Solution
- Update Zephyr's HTTP server to version with path canonicalization.
- Ensure static-filesystem resource type is not exposed.
- Validate filesystem access controls.
- Remove dot segments from URL paths.
Public PoC/Exploit Available at Github
CVE-2026-8023 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
PoC for CVE-2026-8023: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CMake Linker Script C
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-8023 vulnerability anywhere in the article.