CVE-2025-46726 — langroid
Fix: langroid/langroid@36e7e7dCVE-2025-46726 is a XML External Entity (XXE) vulnerability in langroid. A fix is available for langroid — see the affected versions and patch details below.
Langroid Vulnerable to XXE Injection via XMLToolMessage
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
langroidReal-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
Summary
A LLM application leveraging XMLToolMessage class may be exposed to untrusted XML input that could result in DoS and/or exposing local files with sensitive information.
Details
XMLToolMessage uses lxml without safeguards:
https://github.com/langroid/langroid/blob/df6227e6c079ec22bb2768498423148d6685acff/langroid/agent/xml_tool_message.py#L51-L52
lxml is vulnerable to quadratic blowup attacks and processes external entity declarations for local files by default.
Check here: https://pypi.org/project/defusedxml/#python-xml-libraries
PoC
A typical Quadratic blowup XML payload looks like this:
<!DOCTYPE bomb [
<!ENTITY a "aaaaaaaaaa">
<!ENTITY b "&a;&a;&a;&a;&a;&a;&a;&a;&a;&a;">
<!ENTITY c "&b;&b;&b;&b;&b;&b;&b;&b;&b;&b;">
]>
<bomb>&c;</bomb>
Here, &a; expands to 10 characters, &b; expands to 100, and &c; expands to 1000, causing exponential memory usage and potentially crashing the application.
Fix
Langroid 0.53.4 initializes XMLParser with flags to prevent XML External Entity (XXE), billion laughs, and external DTD attacks by disabling entity resolution, DTD loading, and network access.
https://github.com/langroid/langroid/commit/36e7e7db4dd1636de225c2c66c84052b1e9ac3c3
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | langroid | all versions | 0.53.4pip install --upgrade 'langroid==0.53.4' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for langroid, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update langroid to 0.53.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-46726 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-2025-46726 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-46726. 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-2025-46726 in your dependencies?
O3 Security finds CVE-2025-46726 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.