How severe is CVE-2025-34291?

CVE-2025-34291 has a CVSS 4.0 base score of 9.4 (CRITICAL). EPSS estimates a 92.8% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2025-34291: Langflow <= 1.6.9 CORS Misconfiguration to Token

Q: 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 bu

CISA Known Exploited Vulnerabilities

Langflow Origin Validation Error Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2026-05-21

Remediation due

2026-06-04

Required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

CISA notes
This vulnerability could affect an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see: https://github.com/langflow-ai/langflow ; https://github.com/langflow-ai/langflow/releases/tag/v1.9.3; https://github.com/langflow-ai/langflow/issues/11465#event-25774545848 ; https://nvd.nist.gov/vuln/detail/CVE-2025-34291

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.

Severity

CVSS 4.0 · CNA9.4 CRITICAL

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

SSVC · CISA-ADP

Exploitationactive

Automatableno

Technical impacttotal

Exploitation Context

as of October 14, 2026

All KEV statistics→

CISA added CVE-2025-34291 to the KEV catalog 167 days after its CVE record was published. The median for entries added in 2026 so far is 15 days.
It is one of 5 Langflow entries in the CISA KEV catalog, and one of 4 added in 2026.
Its current EPSS score (92.8%) is higher than that of 75% of CISA KEV entries.

Affected Products

Vendor	Product	Affected versions
Langflow	Langflow Langflow	0 to 1.6.9

References

3 Links

Exploits & PoCs

https://www.obsidiansecurity.com/blog/cve-2025-34291-critical-account-takeover-and-rce-vulnerability-in-the-langflow-ai-agent-workflow-platform

Third-party advisories

https://www.vulncheck.com/advisories/langflow-cors-misconfiguration-to-token-hijack-and-rce

Product pages

https://github.com/langflow-ai/langflow

Record Details

Published

2025-12-05

Last updated

2026-10-08

Assigner (CNA)

VulnCheck

Credited to

Fenix Qiao (aka 13ph03nix) from Obsidian Security; Shuyang Wang from Obsidian Security

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Tool categories

Application Security Tools

CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.

CVE-2025-34291