CVE-2026-45134Public exploitNetwork attack vector

SSRF via untrusted public prompt deserialization

Published May 27, 2026 · Updated May 27, 2026

Deserialization in LangSmith SDK before Python 0.8.0 and JS/TS 0.6.0 allows remote attackers to redirect application requests. The prompt pull methods deserialize public owner/name manifests as executable configuration, instantiating LangChain objects with attacker-controlled constructor arguments. Exploitation requires an application to pull an untrusted public prompt and use it without validation; model endpoint settings can expose prompts, context, or credentials.

CVSS severity7.1
High
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization in LangSmith SDK before Python 0.8.0 and JS/TS 0.6.0 allows remote attackers to redirect application requests. The prompt pull methods deserialize public owner/name manifests as executable configuration, instantiating LangChain objects with attacker-controlled constructor arguments. Exploitation requires an application to pull an untrusted public prompt and use it without validation; model endpoint settings can expose prompts, context, or credentials.

The record

CVE
CVE-2026-45134
Published
May 27, 2026
Updated
May 27, 2026
Vendor
LangChain
Product
LangSmith SDK
Classifications
Unavailable
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.6.0
  2. Affected versionversion=< 0.8.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

LangChain · LangSmith SDKversion=< 0.6.0; version=< 0.8.0

Published CVSS scores

7.1GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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