{"id":"PYSEC-2026-1519","summary":"LangChain's XMLOutputParser vulnerable to XML Entity Expansion","details":"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\n\nThis primarily affects users that combine an LLM (or agent) with the `XMLOutputParser` and expose the component via an endpoint on a web-service. \n\nThis 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.\n\nA successful attack is predicated on:\n\n1. Usage of XMLOutputParser\n2. Passing of malicious input into the XMLOutputParser either directly or by trying to manipulate an LLM to do so on the users behalf\n3. Exposing the component via a web-service","aliases":["CVE-2024-1455","GHSA-q84m-rmw3-4382"],"modified":"2026-07-07T17:46:47.138281611Z","published":"2026-07-07T11:45:36.601622Z","references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-1455"},{"type":"WEB","url":"https://github.com/langchain-ai/langchain/pull/17250"},{"type":"WEB","url":"https://github.com/langchain-ai/langchain/pull/19653"},{"type":"WEB","url":"https://github.com/langchain-ai/langchain/pull/19660"},{"type":"WEB","url":"https://github.com/langchain-ai/langchain/commit/727d5023ce88e18e3074ef620a98137d26ff92a3"},{"type":"PACKAGE","url":"https://github.com/langchain-ai/langchain"},{"type":"WEB","url":"https://huntr.com/bounties/4353571f-c70d-4bfd-ac08-3a89cecb45b6"},{"type":"PACKAGE","url":"https://pypi.org/project/langchain-core"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-q84m-rmw3-4382"}],"affected":[{"package":{"name":"langchain-core","ecosystem":"PyPI","purl":"pkg:pypi/langchain-core"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.1.35"}]}],"versions":["0.0.1","0.0.10","0.0.11","0.0.12","0.0.13","0.0.13rc1","0.0.13rc2","0.0.2","0.0.3","0.0.4","0.0.5","0.0.6","0.0.7","0.0.8","0.0.9","0.1.0","0.1.1","0.1.10","0.1.11","0.1.12","0.1.12rc1","0.1.13","0.1.14","0.1.15","0.1.15rc1","0.1.15rc2","0.1.16","0.1.17","0.1.18","0.1.19","0.1.2","0.1.20","0.1.21","0.1.22","0.1.23","0.1.24","0.1.25","0.1.26","0.1.27","0.1.28","0.1.29","0.1.3","0.1.30","0.1.31","0.1.32","0.1.33","0.1.33rc1","0.1.34","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/langchain-core/PYSEC-2026-1519.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}