Cyber Resilience

CVE-2026-33732

H3 Srvx ≤ 0.11.13

Published
26 March 2026
Modified
02 April 2026
Patch / advisory
CVSS Score v3.1 4.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS Score 0.0025 16th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-33732 is a medium-severity Use of Incorrectly-Resolved Name or Reference (CWE-706) vulnerability in H3 Srvx. Its CVSS base score is 4.8 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 16th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

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(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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Pathname parsing discrepancy enables middleware bypass on public-facing web server (Node.js adapter), directly facilitating exploitation of the application via crafted absolute URIs.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-33490Same vendor: H3
CVE-2026-33131Same vendor: H3
CVE-2026-23527Same vendor: H3
CVE-2024-55058Shared CWE-706
CVE-2024-27292Shared CWE-706
CVE-2026-41402Shared CWE-706
CVE-2026-57054Shared CWE-706
CVE-2026-33128Same vendor: H3
CVE-2024-57785Shared CWE-706
CVE-2026-33129Same vendor: H3

Affected Assets

h3
srvx
≤ 0.11.13

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • SI-10 Information Input Validation
  • AC-4 Information Flow Enforcement
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly blocks the middleware bypass by enforcing access decisions on the canonical pathname rather than the attacker-supplied absolute URI.

prevent

Requires validation and normalization of the request URI before any pathname-based routing or middleware decisions, eliminating the FastURL parsing discrepancy.

prevent

Enforces information-flow rules on the resolved path component, preventing non-standard schemes from reaching protected middleware handlers.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure-development practices directly prevent incorrect name/reference resolution bugs during coding.

PR.AA-05 partial match
prevents

Enforced authorization boundaries limit damage from an incorrectly resolved reference.

PR.IR-01 partial match
prevents

Logical segmentation and access controls reduce the chance an out-of-sphere resolution succeeds.

PR.PS-01 partial match
prevents

Hardened configuration baselines can constrain allowable name-to-resource mappings.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing can detect incorrect name or reference resolution through fuzzing and negative test cases.

degrades

Network segmentation and routing policies reduce the chance that a mis-resolved name leads to an unintended external resource.

degrades

Segregated networks limit the blast radius when a name or reference resolves outside the intended control sphere.

prevents

Secure SDLC practices include design reviews that can catch incorrect name or reference handling before deployment.

prevents

Application security requirements can mandate validation of all external references and names used at runtime.

prevents

Secure architecture principles discourage reliance on ambient or globally-resolvable names without explicit scoping.

References