{"id":"CVE-2026-27794","state":"PUBLISHED","title":"LangGraph: BaseCache Deserialization of Untrusted Data may lead to Remote Code Execution","description":"LangGraph Checkpoint defines the base interface for LangGraph checkpointers. Prior to version 4.0.0, a Remote Code Execution vulnerability exists in LangGraph's caching layer when applications enable cache backends that inherit from `BaseCache` and opt nodes into caching via `CachePolicy`. Prior to `langgraph-checkpoint` 4.0.0, `BaseCache` defaults to `JsonPlusSerializer(pickle_fallback=True)`. When msgpack serialization fails, cached values can be deserialized via `pickle.loads(...)`. Caching is not enabled by default. Applications are affected only when the application explicitly enables a cache backend (for example by passing `cache=...` to `StateGraph.compile(...)` or otherwise configuring a `BaseCache` implementation), one or more nodes opt into caching via `CachePolicy`, and the attacker can write to the cache backend (for example a network-accessible Redis instance with weak/no auth, shared cache infrastructure reachable by other tenants/services, or a writable SQLite cache file). An attacker must be able to write attacker-controlled bytes into the cache backend such that the LangGraph process later reads and deserializes them. This typically requires write access to a networked cache (for example a network-accessible Redis instance with weak/no auth or shared cache infrastructure reachable by other tenants/services) or write access to local cache storage (for example a writable SQLite cache file via permissive file permissions or a shared writable volume). Because exploitation requires write access to the cache storage layer, this is a post-compromise / post-access escalation vector. LangGraph Checkpoint 4.0.0 patches the issue.","publishedAt":"2026-02-25T16:53:47.176Z","updatedAt":"2026-02-25T21:00:24.430Z","severity":{"score":6.6,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["langchain-ai langgraph-checkpoint"],"affected":[{"vendor":"langchain-ai","product":"langgraph-checkpoint","versions":[{"version":"< 4.0.0","status":"affected"}]}],"references":["https://github.com/langchain-ai/langgraph/security/advisories/GHSA-mhr3-j7m5-c7c9","https://github.com/langchain-ai/langgraph/pull/6677","https://github.com/langchain-ai/langgraph/commit/f91d79d0c86932ded6e3b9f195d5a0bbd5aef99c","https://github.com/langchain-ai/langgraph/releases/tag/checkpoint%3D%3D4.0.0"],"weaknesses":["CWE-502"],"ingestedAt":"2026-10-29T20:11:31.369Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/27xxx/CVE-2026-27794.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-27794","state":"PUBLISHED","datePublished":"2026-02-25T16:53:47.176Z","dateUpdated":"2026-02-25T21:00:24.430Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-02-24T02:31:33.265Z"},"containers":{"cna":{"title":"LangGraph: BaseCache Deserialization of Untrusted Data may lead to Remote Code Execution","descriptions":[{"lang":"en","value":"LangGraph Checkpoint defines the base interface for LangGraph checkpointers. Prior to version 4.0.0, a Remote Code Execution vulnerability exists in LangGraph's caching layer when applications enable cache backends that inherit from `BaseCache` and opt nodes into caching via `CachePolicy`. Prior to `langgraph-checkpoint` 4.0.0, `BaseCache` defaults to `JsonPlusSerializer(pickle_fallback=True)`. When msgpack serialization fails, cached values can be deserialized via `pickle.loads(...)`. Caching is not enabled by default. Applications are affected only when the application explicitly enables a cache backend (for example by passing `cache=...` to `StateGraph.compile(...)` or otherwise configuring a `BaseCache` implementation), one or more nodes opt into caching via `CachePolicy`, and the attacker can write to the cache backend (for example a network-accessible Redis instance with weak/no auth, shared cache infrastructure reachable by other tenants/services, or a writable SQLite cache file). An attacker must be able to write attacker-controlled bytes into the cache backend such that the LangGraph process later reads and deserializes them. This typically requires write access to a networked cache (for example a network-accessible Redis instance with weak/no auth or shared cache infrastructure reachable by other tenants/services) or write access to local cache storage (for example a writable SQLite cache file via permissive file permissions or a shared writable volume). Because exploitation requires write access to the cache storage layer, this is a post-compromise / post-access escalation vector. LangGraph Checkpoint 4.0.0 patches the issue."}],"affected":[{"vendor":"langchain-ai","product":"langgraph-checkpoint","versions":[{"version":"< 4.0.0","status":"affected"}]}],"references":[{"url":"https://github.com/langchain-ai/langgraph/security/advisories/GHSA-mhr3-j7m5-c7c9","name":"https://github.com/langchain-ai/langgraph/security/advisories/GHSA-mhr3-j7m5-c7c9","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/langchain-ai/langgraph/pull/6677","name":"https://github.com/langchain-ai/langgraph/pull/6677","tags":["x_refsource_MISC"]},{"url":"https://github.com/langchain-ai/langgraph/commit/f91d79d0c86932ded6e3b9f195d5a0bbd5aef99c","name":"https://github.com/langchain-ai/langgraph/commit/f91d79d0c86932ded6e3b9f195d5a0bbd5aef99c","tags":["x_refsource_MISC"]},{"url":"https://github.com/langchain-ai/langgraph/releases/tag/checkpoint%3D%3D4.0.0","name":"https://github.com/langchain-ai/langgraph/releases/tag/checkpoint%3D%3D4.0.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":6.6,"baseSeverity":"MEDIUM","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"HIGH","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-502","lang":"en","description":"CWE-502: Deserialization of Untrusted Data","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-02-25T16:53:47.176Z"},"source":{"advisory":"GHSA-mhr3-j7m5-c7c9","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-02-25T21:00:12.555344Z","id":"CVE-2026-27794","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-02-25T21:00:24.430Z"}}]}}}