GHSA-q84m-rmw3-4382 is a medium-severity (CVSS 5.9) CWE-776 vulnerability in langchain-core. O3 Security confirms whether GHSA-q84m-rmw3-4382 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
LangChain's XMLOutputParser vulnerable to XML Entity Expansion
Real-World Exposure
langchain-coreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
The XMLOutputParser in LangChain uses the etree module from the XML parser in the standard python library which has some XML vulnerabilities; see: https://docs.python.org/3/library/xml.html
This primarily affects users that combine an LLM (or agent) with the XMLOutputParser and expose the component via an endpoint on a web-service.
This would allow a malicious party to attempt to manipulate the LLM to produce a malicious payload for the parser that would compromise the availability of the service.
A successful attack is predicated on:
- Usage of XMLOutputParser
- Passing of malicious input into the XMLOutputParser either directly or by trying to manipulate an LLM to do so on the users behalf
- Exposing the component via a web-service
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | langchain-core | all versions | 0.1.35 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for langchain-core. 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.
Fix
Update langchain-core to 0.1.35 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-q84m-rmw3-4382 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 pinpoints whether GHSA-q84m-rmw3-4382 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-q84m-rmw3-4382. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-q84m-rmw3-4382 in your dependencies?
O3 detects GHSA-q84m-rmw3-4382 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.