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CriticalCISA KEVExploited in the wildPublic exploit

Langflow Origin Validation Error Account Takeover and RCE

IdentifiersCVE-2025-34291CWE-346· Origin Validation Error

CVE-2025-34291 is a critical chained vulnerability affecting Langflow versions up to and including 1.6.9. The issue arises from an overly permissive CORS configuration that allows credentialed cross-origin requests from arbitrary origins (e.g., allow_origins='*' with allow_credentials=True), combined with a refresh token cookie configured as SameSite=None and a refresh endpoint that can be invoked cross-origin. In the reported exploit chain, a victim only needs to visit an attacker-controlled webpage while authenticated to Langflow. The malicious origin can then send cross-origin requests that include the victim’s refresh_token_lf cookie and successfully call the /api/v1/refresh endpoint to obtain fresh access_token and refresh_token pairs for the victim session. Those tokens can then be used to access authenticated Langflow functionality, including built-in code-execution features such as the code validation endpoint, resulting in account takeover and arbitrary code execution on the Langflow host. Supporting reporting also notes missing CSRF protections on the refresh flow as part of the chain.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation enables full session hijacking of an authenticated Langflow user, issuance of fresh authentication tokens, access to authenticated API endpoints, and remote code execution through Langflow’s built-in code-execution functionality. The end state is full system compromise of the Langflow host. Because Langflow commonly stores workflow secrets, API keys, database credentials, service tokens, and other sensitive values, compromise can also expose and enable abuse of those secrets, potentially causing downstream compromise of connected SaaS, cloud, database, and internal services. Active exploitation in the wild has been reported, and CISA added the vulnerability to the KEV catalog.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce exposure by restricting Langflow access to trusted networks and trusted origins only, disabling wildcard CORS policies, and preventing credentialed cross-origin requests. Set LANGFLOW_CORS_ORIGINS explicitly to approved origins rather than using '*'. Reconfigure sensitive authentication cookies to SameSite=Lax or SameSite=Strict where operationally possible. Add or enforce CSRF protections and strict origin checks on token refresh endpoints. Monitor for suspicious cross-origin requests, anomalous refresh-token usage, unexpected token issuance, and abuse of authenticated code-execution endpoints. If mitigations cannot be applied safely, discontinue exposure or use of the vulnerable deployment until upgraded.

Remediation

Patch, then assume compromise.

Upgrade Langflow to version 1.7.0 or later. In addition, replace permissive default CORS behavior with an explicit allowlist of trusted origins, and ensure credentialed cross-origin requests are not permitted from arbitrary origins. Reconfigure authentication cookies so refresh/session cookies are not broadly sent cross-site; reporting specifically indicates planned or recommended use of SameSite=Lax or SameSite=Strict instead of SameSite=None where feasible. Review and harden the refresh flow with proper CSRF and origin-validation protections. For potentially exposed or compromised instances, audit and rotate stored API keys, tokens, and other secrets accessible from Langflow.
PUBLIC EXPLOITS

Exploits

No valid public exploits. Mallory filtered out 2 candidates as fakes, detection scripts, or README-only repos.

VALID 0 / 2 TOTALView more in app

All candidate exploits were filtered out by Mallory's validation.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
LangflowLangflowapplication

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What this page doesn’t show

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Exposure mapping

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Threat actor evidence8

Every observed campaign linking this CVE to a named adversary.

Associated malware2

Malware families riding this exploit, with evidence and IOCs.

Detection signatures2

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Vendor-by-vendor mapping

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Social activity44

Community discussion across Reddit, Mastodon, and other social sources.