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PatchSiren cyber security CVE debrief

CVE-2026-59152 langchain-ai CVE debrief

The LangSmith Client SDKs provide software development kits for interacting with the LangSmith platform. Prior to version 0.8.18, an attacker who can send an HTTP request to a server running the LangSmith SDK's TracingMiddleware can cause that server to read an arbitrary file from its local filesystem and upload the contents to LangSmith as a trace attachment. Depending on how the distributed trace system is deployed, triggering a read may not require authentication. Retrieving the contents requires read access to the LangSmith workspace the traces are sent to. The net effect is a trust-boundary crossing: a party with workspace trace-read access gains the ability to read files from any server running TracingMiddleware, a capability outside that workspace's intended trust boundary. This vulnerability is fixed in version 0.8.18.

Vendor
langchain-ai
Product
langsmith-sdk
CVSS
MEDIUM 5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-06
Original CVE updated
2026-07-07
Advisory published
2026-07-06
Advisory updated
2026-07-07

Who should care

Organizations using LangSmith Client SDKs, especially those with multiple workspaces or shared access, should assess their exposure and upgrade to version 0.8.18 or later. Low-privilege workspace members, contractors, or compromised teammate accounts could potentially exploit this vulnerability to read sensitive files.

Technical summary

The LangSmith Client SDKs' TracingMiddleware is vulnerable to a file read and upload issue. An attacker can send an HTTP request to a server running TracingMiddleware, causing it to read an arbitrary file and upload it as a trace attachment to LangSmith. This issue allows for a trust-boundary crossing, enabling parties with workspace trace-read access to read files from servers running TracingMiddleware. The vulnerability is identified as CWE-22, CWE-346, and CWE-843.

Defensive priority

Medium priority due to the potential for sensitive file exposure and the relatively low CVSS score of 5.

Recommended defensive actions

  • Upgrade LangSmith Client SDKs to version 0.8.18 or later
  • Review and restrict access to LangSmith workspaces
  • Monitor for suspicious TracingMiddleware activity
  • Implement additional authentication for trace uploads if possible
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record was published on 2026-07-06T16:16:37.413Z and was last modified on 2026-07-07T16:16:41.340Z. The NVD entry is currently Awaiting Analysis. Limited details are available about the specific exploitation or affected systems.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-59152 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-59152

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-59152 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-59152

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.