GHSA-mhr3-j7m5-c7c9 · Severity: medium · Ecosystem: pip — LangGraph: BaseCache Deserialization of Untrusted Data may lead to Remote Code Execution
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.
Conclusion & alert: CVE-2026-27794 is rated Moderate Risk (46.5/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.35%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-03-29 | 0.32% | 0.35% | +0.03% |
| 2 | 2026-03-03 | 0.24% | 0.32% | +0.08% |
| 3 | 2026-02-26 | — | 0.24% | — |
Full EPSS history (3 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.6 | 3.1 | MEDIUM |
|
0.7 | 5.9 | [email protected] |
GHSA-mhr3-j7m5-c7c9 · Severity: medium · Ecosystem: pip — LangGraph: BaseCache Deserialization of Untrusted Data may lead to Remote Code Execution
| vendor | priority | summary | link |
|---|---|---|---|
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2026-27794 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| No affected products in dataset. | |||