CVE-2026-33872 — nodejs
Fix: revelrylabs/elixir-nodejs#105CVE-2026-33872 is a CWE-362 vulnerability in nodejs. A fix is available for nodejs — see the affected versions and patch details below.
elixir-nodejs has Cross-User Data Leakage or Information Disclosure due to Worker Protocol Race Condition
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-33872.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
nodejsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Hex packages — download data is not available via public APIs for these ecosystems.
Description
elixir-nodejs provides an Elixir API for calling Node.js functions. A vulnerability in versions prior to 3.1.4 results in Cross-User Data Leakage or Information Disclosure due to a race condition in the worker protocol. The lack of request-response correlation creates a "stale response" vulnerability. Because the worker does not verify which request a response belongs to, it may return the next available data in the buffer to an unrelated caller. In high-throughput environments where the library processes sensitive user data (e.g., PII, authentication tokens, or private records), a timeout or high concurrent load can cause Data A (belonging to User A) to be returned to User B. This may lead to unauthorized information disclosure that is difficult to trace, as the application may not throw an error but instead provide "valid-looking" yet entirely incorrect and private data to the wrong session. The issue is fixed in v3.1.4.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💧Hex | nodejs | all versions | 3.1.4mix deps.update nodejs |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nodejs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update nodejs to 3.1.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33872 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-33872 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-33872. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-33872 in your dependencies?
O3 Security finds CVE-2026-33872 across Hex dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.