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MEDIUM severity

GHSA-hh8v-jmh3-9437

MEDIUM

GHSA-hh8v-jmh3-9437 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in sockjs. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether GHSA-hh8v-jmh3-9437 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Cross-site scripting in SocksJS-node

Also known asCVE-2020-8823
Published
Apr 13, 2021
Updated
Mar 13, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
1 known
Exploitation data as of Mar 13, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

777other npm packages depend on this — each one inherits the vulnerability until it's patched upstream
sockjsnpm
15.4Mdownloads / week

Description

htmlfile in lib/transport/htmlfile.js in SockJS before 0.3.0 is vulnerable to Reflected XSS via the /htmlfile c (aka callback) parameter.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
📦npmsockjsall versions0.3.0
Exploits & PoCs
1

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for sockjs. 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.

  2. Fix

    Update sockjs to 0.3.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hh8v-jmh3-9437 is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 pinpoints whether GHSA-hh8v-jmh3-9437 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-hh8v-jmh3-9437. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

htmlfile in lib/transport/htmlfile.js in SockJS before 0.3.0 is vulnerable to Reflected XSS via the /htmlfile c (aka callback) parameter.
O3 Security · Impact-Aware SCA

Is GHSA-hh8v-jmh3-9437 in your dependencies?

O3 detects GHSA-hh8v-jmh3-9437 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

GHSA-hh8v-jmh3-9437: Cross-site scripting in… | O3 Security