GitHub Advisoryadvisory · npm
GHSA-p36q-q72m-gchr srvx is vulnerable to middleware bypass via absolute URI in request line
MEDIUM
Official page ↗
- Aliases
- CVE-2026-33732
- Ecosystem
- npm
- Packages
- srvx
- Severity
- Moderate
- CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
- Weaknesses
- CWE-706
- Reviewed
- 2026-03-26
Affected packages
• npm srvx: < 0.11.13 → fixed in 0.11.13
Description
Summary
A pathname parsing discrepancy in srvx's `FastURL` allows middleware bypass on the Node.js adapter when a raw HTTP request uses an absolute URI with a non-standard scheme (e.g. `file://`).
Details
When Node.js receives an absolute URI in the request line (e.g. `GET file://hehe?/internal/run HTTP/1.1`), `req.url` is set verbatim to `file://hehe?/internal/run`. Since this doesn't start with `/`, `NodeRequestURL` passes it directly to `FastURL` as a string, which stores it in `#href` for lazy manual parsing.
`FastURL#getPos()` locates the pathname by finding `://` then scanning for the next `/` — but this fails for URLs like `file://hehe?/internal/run` where a `?` appears before the first `/` after the authority. The manual parser extracts pathname as `/internal/run`, while native `URL` correctly parses it as pathname `/` with search `?/internal/run`.
This discrepancy means the router (using the fast-path) matches `/internal/run`, but if any middleware triggers a deopt to native `URL` (e.g. by accessing `hostname`), subsequent middleware sees a different pathname — bypassing route-based middleware guards.
This is a bypass of CVE-2026-33131.
Impact
Route-based middleware (auth guards, rate limiters, etc.) can be bypassed on the Node.js adapter when a prior middleware triggers `FastURL` deopt. Requires sending a raw HTTP request (not possible from browsers).
Fix
srvx `FastURL` constructor now deopts to native `URL` for any string not starting with `/`, ensuring consistent pathname resolution.
Related
Alias · CVE (1)
- CVE-2026-33732 srvx is a universal server based on web standards. vulnerability
Weakness · CWE (1)
- CWE-706 Use of Incorrectly-Resolved Name or Reference weakness