CVE-2025-34291

Langflow Origin Validation Error

8.8 HIGHActively exploited (CISA KEV)Public exploitEPSS 92.8%

Published5 Dec 2025
Added to CISA KEV21 May 2026
Remediation due4 Jun 2026

Langflow contains an origin validation error vulnerability in which an overly permissive CORS configuration combined with a refresh token cookie configured as SameSite=None allows a malicious webpage to perform cross-origin requests that include credentials and successfully call the refresh endpoint. This could allow the attacker to execute arbitrary code and achieve full system compromise via obtained tokens that permit access to authenticated endpoints.

Added to KEV: 21 May 2026Federal remediation due: 4 Jun 2026

Description

Langflow versions up to and including 1.6.9 contain a chained vulnerability that enables account takeover and remote code execution. An overly permissive CORS configuration (allow_origins='*' with allow_credentials=True) combined with a refresh token cookie configured as SameSite=None allows a malicious webpage to perform cross-origin requests that include credentials and successfully call the refresh endpoint. An attacker-controlled origin can therefore obtain fresh access_token / refresh_token pairs for a victim session. Obtained tokens permit access to authenticated endpoints — including built-in code-execution functionality — allowing the attacker to execute arbitrary code and achieve full system compromise.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredLow

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

Langflow≤ 1.6.9

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

https://github.com/langflow-ai/langflowProduct
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-34291US Government Resource
https://www.crowdsec.net/vulntracking-report/cve-2025-34291Third Party Advisory
https://www.obsidiansecurity.com/blog/cve-2025-34291-critical-account-takeover-and-rce-vulnerability-in-the-langflow-ai-agent-workflow-platformExploitMitigationThird Party Advisory
https://www.vulncheck.com/advisories/langflow-cors-misconfiguration-to-token-hijack-and-rceThird Party Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2025-34291 being actively exploited?

Yes. CVE-2025-34291 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 21 May 2026.

How severe is CVE-2025-34291?

CVE-2025-34291 has a CVSS 3.1 base score of 8.8, rated high. EPSS estimates a 92.8% probability of exploitation.

Which products are affected by CVE-2025-34291?

Affected products include Langflow.

How do I fix CVE-2025-34291?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2025-34291 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, a risk for it never ranks below high, and the update that fixes it moves to the Emergency patch lane. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.