CVE-2026-33732
srvx is vulnerable to middleware bypass via absolute URI in request line
srvx is a universal server based on web standards. Prior to version 0.11.13, 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://). Starting in version 0.11.13, the FastURL constructor now deopts to native URL for any string not starting with /, ensuring consistent pathname resolution.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
4.8
srvx is vulnerable to middleware bypass via absolute URI in request line
srvx is a universal server based on web standards. Prior to version 0.11.13, 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://). Starting in version 0.11.13, the FastURL constructor now deopts to native URL for any string not starting with /, ensuring consistent pathname resolution.
- Record
CVE-2026-33732- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-706
- Updated
- 2026-11-02
EUVDEUVD-2026-16291
4.8
srvx is a universal server based on web standards. Prior to version 0.11.13, 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://). Starting in version 0.11.13, the FastURL constructor now deopts to native URL for any string not starting with /, ensuring consistent pathname resolution.
- Record
EUVD-2026-16291- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-p36q-q72m-gchr
4.8
srvx is vulnerable to middleware bypass via absolute URI in request line
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.
- Record
GHSA-p36q-q72m-gchr- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-706
- Updated
- 2026-11-02
NVD
4.8
srvx is a universal server based on web standards. Prior to version 0.11.13, 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://). Starting in version 0.11.13, the FastURL constructor now deopts to native URL for any string not starting with /, ensuring consistent pathname resolution.
- Record
CVE-2026-33732- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-706
- Updated
- 2026-11-02
OSV
4.8
srvx is vulnerable to middleware bypass via absolute URI in request line
srvx is a universal server based on web standards. Prior to version 0.11.13, 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://). Starting in version 0.11.13, the FastURL constructor now deopts to native URL for any string not starting with /, ensuring consistent pathname resolution.
- Record
CVE-2026-33732- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-706
- Updated
- 2026-11-02
OSVGHSA-p36q-q72m-gchr
4.8
srvx is vulnerable to middleware bypass via absolute URI in request line
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.
- Record
GHSA-p36q-q72m-gchr- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-706
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
srvxnpm |
before 0.11.13 | 0.11.13 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-33732 is a medium vulnerability (CVSS 4.8) in H3 Srvx, published March 26, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.26%, the 17th percentile. Fixed in srvx 0.11.13.
References
github.com/h3js/h3/security/advisories/GHSA-p36q-q72m-gchr
github.com/h3js/srvx/commit/de0d69901c357f36a39b7e13eebef6c930652baa
github.com/h3js/srvx/releases/tag/v0.11.13
nvd.nist.gov/vuln/detail/CVE-2026-33732
github.com/advisories/GHSA-p36q-q72m-gchr
github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33732.json
github.com/h3js/srvx