CVE-2026-48775
Description
A flaw was found in LangGraph. This vulnerability allows an attacker with high privileges and adjacent network access to modify checkpoint data. By manipulating these stored checkpoint bytes, an attacker can trigger insecure deserialization, leading to arbitrary code execution when the checkpoint is loaded. This issue is considered a defense-in-depth concern, as it requires prior unauthorized access to the checkpoint's backing store.
Statement
A flaw was found in LangGraph's SQLite checkpoint implementation. The JsonPlusSerializer can reconstruct Python objects from JSON checkpoint payloads. If an attacker gains write access to the checkpoint backing store, they can modify checkpoint bytes to achieve code execution at checkpoint load time. This is a defense-in-depth issue — the prerequisite of checkpoint-store write access already implies a serious incident in most deployments.
Mitigation
Upgrade to LangGraph checkpoint version 4.1.1 or later. As a defense-in-depth measure, restrict write access to the checkpoint backing store to only trusted application components.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.4 | N/A | 6.8 |
| Attack Vector | Adjacent Network | N/A | Adjacent Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | High | N/A | High |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:A/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Application Data; Unexpected State
Attackers can modify unexpected objects or data that was assumed to be safe from modification. Deserialized data or code could be modified without using the provided accessor functions, or unexpected functions could be invoked.
Availability
Technical Impact: DoS: Resource Consumption (CPU)
If a function is making an assumption on when to terminate, based on a sentry in a string, it could easily never terminate.
Other
Technical Impact: Varies by Context
The consequences can vary widely, because it depends on which objects or methods are being deserialized, and how they are used. Making an assumption that the code in the deserialized object is valid is dangerous and can enable exploitation. One example is attackers using gadget chains to perform unauthorized actions, such as generating a shell.
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