Deserialization in Langchain Langgraph-Checkpoint
CVE-2026-48775
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.
Vulnerability class: Insecure Deserialization
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.002 (14.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 14.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.002 · change: -0.005
Affected products
- Langchain Langgraph-Checkpoint
- Langchain-Ai Langgraph — versions < 1.2.2
- Langchain-Ai Langraph-Checkpoint — versions < 4.1.1
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-48775?
- CVE-2026-48775 is a medium-severity vulnerability in Langchain Langgraph-Checkpoint, classified under Deserialization of Untrusted Data. CVSS score: 6.8/10. Published 2026-06-16.
- How severe is CVE-2026-48775?
- Medium severity. CVSS v3 base score is 6.8 out of 10.