Actively exploited · Published Dec 5, 2025 · Assigned by VulnCheck
CVE-2025-34291Langflow <= 1.6.9 CORS Misconfiguration to Token Hijack & RCE
Critical 9.4 Exploited
In plain English
A critical-severity security flaw in Langflow from Langflow. Attackers are actively exploiting it in the wild (listed by CISA on May 21, 2026). The chance it is exploited in the next 30 days is estimated at 93.2% (higher than 99.8% of all known vulnerabilities). Ready-made attack tooling exists: Nuclei, public proof-of-concept code. Fixed versions are available - upgrade the affected package.
CISA guidance
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Federal agencies must remediate by Jun 4, 2026.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | langflow | 1.7.0 | GHSA-577h-p2hh-v4mv |
| PyPI | langflow | 1.7.0 | PYSEC-2025-78 |
Affected products (as reported)
Weakness: CWE-346 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
References
- https://www.obsidiansecurity.com/blog/cve-2025-34291-critical-account-takeover-and-rce-vulnerability-in-the-langflow-ai-agent-workflow-platform technical-description, exploit
- https://github.com/langflow-ai/langflow product
- https://www.vulncheck.com/advisories/langflow-cors-misconfiguration-to-token-hijack-and-rce third-party-advisory
- https://www.crowdsec.net/vulntracking-report/cve-2025-34291 third-party-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-34291 government-resource