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VulnerabilityPublished

CVE-2026-27794: langchain-ai langgraph-checkpoint · Deserialization of Untrusted Data

Affects langchain-ai langgraph-checkpointSource CVE Database V5

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Not known to be exploited · CVSS 6.6 Medium : upgrade to 4.0.0 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score
6.6Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.8% chance of exploitation in 30 days – higher than 57% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 4.0.0
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Feb 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

What to do

Upgrade langchain-ai langgraph-checkpoint to 4.0.0.

Affected software

ProductAffectedFixed in
langchain-ailanggraph-checkpointAffected
  • <4.0.0
Fixed in
  • 4.0.0
PyPIlanggraph-checkpointpkg:pypi/langgraph-checkpointOther threatsAffected
  • <4.0.0
Fixed in
  • 4.0.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade langgraph-checkpoint to version 4.0.0 or later, where this vulnerability is patched. If upgrading is not immediately possible, ensure that cache backends are not enabled or that cache storage is not writable by untrusted parties. Restrict write access to cache backends such as Redis instances and local cache files to trusted users and processes only. Patch status is confirmed fixed in version 4.0.0.

Description

A deserialization vulnerability (CWE-502) exists in langchain-ai's langgraph-checkpoint versions prior to 4.0.0. The issue arises when applications explicitly enable caching with cache backends inheriting from BaseCache and nodes opt into caching via CachePolicy. The default serializer falls back to pickle.loads for certain data, allowing remote code execution if an attacker can write malicious serialized data into the cache backend. Exploitation requires write access to the cache storage, making this a post-compromise escalation vector. The vulnerability is patched in langgraph-checkpoint version 4.0.0.

References

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