{"id":"CVE-2025-46726","aliases":["GHSA-pw95-88fg-3j6f","PYSEC-2026-1532"],"url":"https://o3.security/vulnerability/CVE-2025-46726","summary":"Langroid Vulnerable to XXE Injection via XMLToolMessage","details":"### Summary\nA 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.\n\n### Details\n`XMLToolMessage` uses `lxml` without safeguards:\nhttps://github.com/langroid/langroid/blob/df6227e6c079ec22bb2768498423148d6685acff/langroid/agent/xml_tool_message.py#L51-L52\n`lxml` is vulnerable to quadratic blowup attacks and processes external entity declarations for local files by default. \nCheck here: https://pypi.org/project/defusedxml/#python-xml-libraries\n\n### PoC\nA typical Quadratic blowup XML payload looks like this:\n```xml\n<!DOCTYPE bomb [\n<!ENTITY a \"aaaaaaaaaa\">\n<!ENTITY b \"&a;&a;&a;&a;&a;&a;&a;&a;&a;&a;\">\n<!ENTITY c \"&b;&b;&b;&b;&b;&b;&b;&b;&b;&b;\">\n]>\n<bomb>&c;</bomb>\n```\nHere, &a; expands to 10 characters, &b; expands to 100, and &c; expands to 1000, causing exponential memory usage and potentially crashing the application.\n \n### Fix\nLangroid 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.\nhttps://github.com/langroid/langroid/commit/36e7e7db4dd1636de225c2c66c84052b1e9ac3c3","published":"2025-05-05T19:21:19.597Z","modified":"2026-08-12T03:51:34.147890040Z","cvss":null,"epss":{"score":0.00621,"percentile":0.48145,"asOf":"2026-09-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"langroid","fixedVersion":"0.53.4"}],"fix":{"url":"https://github.com/langroid/langroid/commit/36e7e7db4dd1636de225c2c66c84052b1e9ac3c3","label":"langroid/langroid@36e7e7d"},"references":[{"type":"WEB","url":"https://github.com/langroid/langroid/blob/df6227e6c079ec22bb2768498423148d6685acff/langroid/agent/xml_tool_message.py#L51-L52"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/46xxx/CVE-2025-46726.json"},{"type":"ADVISORY","url":"https://github.com/langroid/langroid/security/advisories/GHSA-pw95-88fg-3j6f"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-46726"},{"type":"FIX","url":"https://github.com/langroid/langroid/commit/36e7e7db4dd1636de225c2c66c84052b1e9ac3c3"},{"type":"PACKAGE","url":"https://github.com/langroid/langroid"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:34.147890040Z"}}