{"id":"CVE-2026-44843","aliases":["GHSA-pjwx-r37v-7724","PYSEC-2026-2564"],"url":"https://o3.security/vulnerability/CVE-2026-44843","summary":"LangChain: Unsafe deserialization of attacker-controlled LangChain objects through overly broad `load()` allowlists","details":"LangChain is a framework for building agents and LLM-powered applications. Prior to 0.3.85 and 1.3.3, LangChain contains older runtime code paths that deserialize run inputs, run outputs, or other application-controlled payloads using overly broad object allowlists. These paths may call load() with allowed_objects=\"all\". This does not enable arbitrary Python object deserialization, but it does allow any trusted LangChain-serializable object to be revived, which is broader than these runtime paths require. As a result, attacker-supplied LangChain serialized constructor dictionaries may cause trusted runtime paths to instantiate classes with untrusted constructor arguments. This vulnerability is fixed in 0.3.85 and 1.3.3.","published":"2026-05-26T19:47:35.328Z","modified":"2026-08-07T11:51:11.157284440Z","cvss":{"score":8.2,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"langchain-core","fixedVersion":"1.3.3"},{"ecosystem":"PyPI","name":"langchain-core","fixedVersion":"0.3.85"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44843.json"},{"type":"ADVISORY","url":"https://github.com/langchain-ai/langchain/security/advisories/GHSA-pjwx-r37v-7724"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44843"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:51:11.157284440Z"}}