---
title: "CVE-2025-34291: Langflow Origin Validation Error Vulnerability"
url: https://erroneo.us/security/cve/CVE-2025-34291/
description: "CVE-2025-34291 (Langflow Langflow): Exploited in the wild (CISA KEV). Langflow versions up to and including 1.6.9 contain a chained vulnerability that…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-12-05
date_modified: 2026-10-21
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-34291"
kev: true
cvss: 9.4
epss: 0.92808
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-34291: Langflow Origin Validation Error Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run Langflow Langflow. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-05-21, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-06-04 ; treat that as the outer limit, not the target.
- EPSS 92.8% , percentile 99.8: FIRST’s model estimates a 92.8% chance of exploitation activity in the next 30 days, higher than 99.8% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Only applies if your dependency tree includes langflow (PyPI) <= 1.6.9, fixed in 1.7.0 . Check your lockfile, including transitive dependencies.
- Editorial verdict: Act now. Langflow CVE-2026-9198: Exploited Unauthenticated RCE — Langflow is now the most repeatedly exploited AI-agent builder on CISA's list; any network-reachable instance below 1.10.1 should be patched today and checked for compromise.

## What it is

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 (alloworigins='' with allowcredentials=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 accesstoken / refreshtoken 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

- PyPI `langflow` <= 1.6.9 → fixed: 1.7.0

## Affected products (CVE record)

- Langflow Langflow: <= 1.6.9

## Severity

- VulnCheck CVSS 4.0: 9.4 `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`
- GitHub CVSS 4.0: 9.4 `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`

## Exploitation

- CISA KEV: added 2026-05-21; federal due date 2026-06-04. Known ransomware use: Unknown.
- CISA 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 SSVC assessment: exploitation active , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 92.81% probability of exploitation activity in the next 30 days; percentile 99.8.

## Sources

- [Listed in CISA KEV notes (github.com)](https://github.com/langflow-ai/langflow)
- [Listed in CISA KEV notes (github.com)](https://github.com/langflow-ai/langflow/releases/tag/v1.9.3)
- [Listed in CISA KEV notes (github.com)](https://github.com/langflow-ai/langflow/issues/11465#event-25774545848)
- [GitHub Advisory GHSA-577h-p2hh-v4mv](https://github.com/advisories/GHSA-577h-p2hh-v4mv)
- [CVE.org record CVE-2025-34291](https://www.cve.org/CVERecord?id=CVE-2025-34291)
- [NVD entry CVE-2025-34291](https://nvd.nist.gov/vuln/detail/CVE-2025-34291)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-34291)
- [obsidiansecurity.com](https://www.obsidiansecurity.com/blog/cve-2025-34291-critical-account-takeover-and-rce-vulnerability-in-the-langflow-ai-agent-workflow-platform)
- [vulncheck.com](https://www.vulncheck.com/advisories/langflow-cors-misconfiguration-to-token-hijack-and-rce)
- [crowdsec.net](https://www.crowdsec.net/vulntracking-report/cve-2025-34291)
- [github.com](https://github.com/langflow-ai/langflow/pull/10139)
- [github.com](https://github.com/langflow-ai/langflow/pull/10696)
- [github.com](https://github.com/langflow-ai/langflow/pull/9240)
- [github.com](https://github.com/langflow-ai/langflow/pull/9441)
- [github.com](https://github.com/pypa/advisory-database/tree/main/vulns/langflow/PYSEC-2025-78.yaml)

---
Source page: https://erroneo.us/security/cve/CVE-2025-34291/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt