Langroid Allows XXE Injection via XMLToolMessage

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

7.8 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/E:P · score source

EPSS

• CVE-2025-46726: 0.65% estimated exploitation activity in the next 30 days; percentile 51.11 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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/xmltoolmessage.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: 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.…

Published by the source

5 May 2025, 20:40 UTC

Last modified by the source

7 Jul 2026, 17:56 UTC

Source last checked

26 Oct 2026, 13:32 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-pw95-88fg-3j6f

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-pw95-88fg-3j6f

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# Patch Next advisory brief: CVE-2025-46726

Advisory: Langroid Allows XXE Injection via XMLToolMessage
IDs: CVE-2025-46726, GHSA-pw95-88fg-3j6f
Record: https://patchnext.com/advisories/cve-2025-46726 (revision 3, source checked 26 Oct 2026, 13:32 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: langroid 0.53.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI langroid: affected < 0.53.4; fixed in 0.53.4

## Suggested inspection (read-only)
- `python -m pip show langroid`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on langroid.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-pw95-88fg-3j6f (OSV record GHSA-pw95-88fg-3j6f lists affected ranges: PyPI langroid >=0 <0.53.4 (fixed))
- Verified: https://github.com/advisories/GHSA-pw95-88fg-3j6f (GitHub-reviewed advisory GHSA-pw95-88fg-3j6f lists affected ranges: PyPI langroid >=0 <0.53.4)

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