CVE-2025-34291

CVE-2025-34291 is a high-severity vulnerability in Langflow with a CVSS 3.x base score of 8.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2026-05-21). The underlying weakness is classified as CWE-346.

Key facts

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.

Frequently asked questions

What is CVE-2025-34291?
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.
How severe is CVE-2025-34291?
CVE-2025-34291 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-34291 being actively exploited?
Yes. CVE-2025-34291 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-05-21, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2025-34291?
CVE-2025-34291 affects Langflow. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-34291?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2025-34291 have an EU (EUVD) identifier?
Yes. CVE-2025-34291 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-201507. It is also flagged as exploited in the EUVD (since 2026-05-21).
When was CVE-2025-34291 published?
CVE-2025-34291 was published on 2025-12-05 and last updated on 2026-06-17.

References

Affected products (1)

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