GHSA-vfp3-v2gw-7wfq is a high-severity (CVSS 7.5) Path Traversal vulnerability in github.com/labstack/echo/v5. O3 Security confirms whether GHSA-vfp3-v2gw-7wfq is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Echo: Encoded slash (%2F) bypasses route-level protection and exposes static files
Real-World Exposure
github.com/labstack/echo/v5🐹github.com/labstack/echo/v4🐹github.com/labstack/echoReal-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
Echo's router and static file handler disagree on URL path decoding. The router matches routes using the raw encoded path (preserving %2F as-is), while StaticDirectoryHandler unescapes %2F to / before resolving filesystem paths. This allows an attacker to bypass route-level access controls and read static files without authorization.
Details
Root cause 1 — router.go lines 798-802:
The router uses req.URL.RawPath for route matching when useEscapedPathForRouting is false (the default). This means /admin%2Fsecret.txt is treated as a single path segment and does NOT match the /admin/* route pattern.
if !r.useEscapedPathForRouting && req.URL.RawPath != "" {
path = req.URL.RawPath
}
Root cause 2 — echo.go lines 559-568:
StaticDirectoryHandler calls url.PathUnescape() on the path parameter before opening files. This converts %2F back to /, resolving admin/secret.txt on disk.
if !disablePathUnescaping {
tmpPath, err := url.PathUnescape(p)
p = tmpPath
}
name := filepath.ToSlash(filepath.Clean(strings.TrimPrefix(p, "/")))
PoC (Screenshot)
Sample: <img width="1291" height="970" alt="image" src="https://github.com/user-attachments/assets/0bc58059-3e6d-4678-ab25-a5c79b006738" />
403: <img width="526" height="194" alt="image" src="https://github.com/user-attachments/assets/2f55ffdd-87b2-4a1b-8a13-130ebad0f257" />
Bypass with encoded slash: <img width="592" height="203" alt="image" src="https://github.com/user-attachments/assets/1191cd39-ae8f-4d7e-8fb1-cb9cf31f484f" />
Impact
Unauthorized static file disclosure. Applications that protect route prefixes with authentication middleware while also serving static files from a broader root are vulnerable. An attacker only needs to encode the slash (/ → %2F) in the URL to bypass all route-level protection.
Common affected pattern:
adminGroup := e.Group("/admin", authMiddleware)
e.StaticFS("/", os.DirFS("public"))
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/labstack/echo/v5 | all versions | 5.2.0 |
| 🐹Go | github.com/labstack/echo/v4 | all versions | 4.15.3 |
| 🐹Go | github.com/labstack/echo | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/labstack/echo/v5. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/labstack/echo/v5 to 5.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vfp3-v2gw-7wfq 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 pinpoints whether GHSA-vfp3-v2gw-7wfq is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-vfp3-v2gw-7wfq. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-vfp3-v2gw-7wfq in your dependencies?
O3 detects GHSA-vfp3-v2gw-7wfq across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.