Vulnerability · Published Jun 16, 2026 · Assigned by GitHub_M
CVE-2026-48775LangGraph Checkpoint: Unsafe JSON deserialization in checkpoint loading
Medium 6.8
In plain English
A medium-severity unsafe deserialization in langgraph from langchain-ai. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
LangGraph SQLite Checkpoint is an implementation of LangGraph CheckpointSaver that uses SQLite DB (both sync and async, via aiosqlite). In versions 4.1.0 and prior, the JsonPlusSerializer can reconstruct Python objects from JSON checkpoint payloads. Under conditions where someone could modify checkpoint bytes at rest in the backing store, the deserialization path could reconstruct objects beyond what the application expects, which could in turn result in code execution at checkpoint load time. This is a defense-in-depth issue. The affected behavior is reachable only when checkpoint bytes at rest in the backing store can be modified by an unauthorized party. In most deployments that prerequisite already implies a serious incident; the additional concern is turning "checkpoint-store write access" into code execution in the application runtime. This issue has been fixed in version 4.1.1.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | langgraph-checkpoint | 4.1.1 | GHSA-fjqc-hq36-qh5p |
| PyPI | langgraph-checkpoint | 4.1.1 | PYSEC-2026-2573 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| langchain-ai | langgraph | < 1.2.2 |
| langchain-ai | langraph-checkpoint | < 4.1.1 |
Weakness: CWE-502, CWE-913 · Vector: CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H