Unsafe Deserialization in langgraph-checkpoint (CVE-2026-27794)
Summary
Vulnerability in langgraph-checkpoint (CVE-2026-27794). Successful exploitation can lead to full system takeover. Exploitable via BaseCache. Mitigation: upgrade to 4.0.0 or later.
Original description
The description as published by the source.
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 exp…
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-27794 has been found in langgraph-checkpoint.
Attackers can target a specific entry point like BaseCache over the network to misuse the product.
Successful exploitation can lead to full system takeover.
What to do: upgrade langgraph-checkpoint to 4.0.0 or later.
If unsure, ask your IT team or search "langgraph-checkpoint CVE-2026-27794" on the vendor's site.
CVE-2026-27794 (langgraph-checkpoint) — CWE-502
Attack vector: remote (network-reachable) / no user interaction
Attack surface: BaseCache / CachePolicy / JsonPlusSerializer / InMemoryCache
Patched: 4.0.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Unsafe deserialization (CWE-502) exists in langgraph-checkpoint. Attackers reach the vulnerable code path via BaseCache.
Check the vendor advisory for the affected versions of langgraph-checkpoint. Attack surface: BaseCache / CachePolicy / JsonPlusSerializer / InMemoryCache.
Severity: ?. Successful exploitation can lead to full system takeover.
Update to 4.0.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'langgraph-checkpoint' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'langgraph-checkpoint' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
langgraph-checkpointを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade langgraph-checkpoint to 4.0.0ステージング環境で 4.0.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- patch github.com
- patch github.com
- web github.com