# CVE-2026-28277 — langchain-ai langgraph

> As of 2026-03-06, CVE-2026-28277 is a MEDIUM-severity vulnerability in langchain-ai langgraph, CVSS v3.1 6.8, EPSS 0.6% (51.7th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-28277, most recently “LangGraph Checkpointer: Chained SQLi-to-RCE via Unsafe msgpack Deserialization (CVE-2025-67644, CVE-2026-28277, CVE-2026-27022)”.

**Last updated:** 2026-03-06

## What is CVE-2026-28277?

LangGraph SQLite Checkpoint is an implementation of LangGraph CheckpointSaver that uses SQLite DB (both sync and async, via aiosqlite). In version 1.0.9 and prior, LangGraph checkpointers can load msgpack-encoded checkpoints that reconstruct Python objects during deserialization. If an attacker can modify checkpoint data in the backing store (for example, after a database compromise or other privileged write access to the persistence layer), they can potentially supply a crafted payload that triggers unsafe object reconstruction when the checkpoint is loaded. No known patch is public.

The record classifies CVE-2026-28277 under weakness class [CWE-502](https://intel.threadlinqs.com/cwe/CWE-502). Its CVSS v3 base vector states that the flaw is reachable from an adjacent network, needs high-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 236 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 6.8 — MEDIUM (`CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **EPSS (FIRST):** 0.6% probability of exploitation in the next 30 days, higher than 51.7% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 5.5/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-03-05, last modified 2026-03-06

## Is CVE-2026-28277 being exploited?

It currently carries a trending score of 18 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **langchain-ai**: langgraph

## How to fix CVE-2026-28277

Vendor advisory: [https://github.com/langchain-ai/langgraph/security/advisories/GHSA-g48c-2wqr-h844](https://github.com/langchain-ai/langgraph/security/advisories/GHSA-g48c-2wqr-h844). Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

## Threat activity tracking CVE-2026-28277

1 tracked threat in the Threadlinqs corpus references CVE-2026-28277, either in the campaign’s CVE list or as an indicator on the campaign record.

- [LangGraph Checkpointer: Chained SQLi-to-RCE via Unsafe msgpack Deserialization (CVE-2025-67644, CVE-2026-28277, CVE-2026-27022)](https://intel.threadlinqs.com/threat/TL-2026-0778) — CRITICAL · 2026-06-11

## Sources

Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on 2026-10-10. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [github.com](https://github.com/langchain-ai/langgraph/security/advisories/GHSA-g48c-2wqr-h844)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-28277
Full detection coverage and IOCs for threats exploiting CVE-2026-28277 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp