# CVE-2026-33872: elixir-nodejs has Cross-User Data Leakage or Information Disclosure due to Worker Protocol Race Condition

> A race condition in elixir-nodejs allows attackers to leak sensitive user data to unrelated sessions due to missing request-response correlation.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 Mar 2026
- **Updated:** 30 Mar 2026
- **Also known as:** GHSA-rwcr-rpcc-3g9m

## What is CVE-2026-33872?

CVE-2026-33872 is a high-severity vulnerability in revelrylabs elixir-nodejs, published on 27 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official 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.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-33872?

2 open source packages ship an affected version, including nodejs.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `nodejs` | Hex | All versions | 3.1.4 |
| `nodejs` | Hex | All versions | 3.1.4 |

## How do I fix CVE-2026-33872?

Upgrade nodejs to 3.1.4 or later.

## Is CVE-2026-33872 being exploited?

There is no known exploitation of CVE-2026-33872 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33872 and fix it if it is affected.

What it is: CVE-2026-33872 is a high-severity vulnerability in revelrylabs elixir-nodejs, published on 27 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-33872 in the wild and no public exploit code.

Affected packages and fixed versions:
- nodejs (Hex): affected all versions; fixed in 3.1.4
- nodejs (Hex): affected all versions; fixed in 3.1.4

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-33872/ (Markdown: https://insights.sbomify.com/CVE-2026-33872/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33872
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33872
- OSV: https://osv.dev/vulnerability/CVE-2026-33872

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33872/
Summaries are generated and may contain mistakes; the official description above is the record.