Cyber Posture

CVE-2025-34291

HighPublic PoC

Published: 05 December 2025

Published
05 December 2025
Modified
16 January 2026
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.1327 94.2th percentile
Risk Priority 26 60% EPSS · 20% KEV · 20% CVSS

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…

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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.

Mitigating Controls (NIST 800-53 r5)AI

prevent

Requires establishment of secure configuration settings for web applications, directly mitigating the permissive CORS (allow_origins='*') and unsafe SameSite=None cookie configurations exploited in this CVE.

prevent

Mandates timely flaw remediation including patching Langflow to versions beyond 1.6.9, eliminating the chained vulnerability enabling token theft and RCE.

preventdetect

Enforces boundary protections such as web application firewalls or proxies to monitor and restrict unauthorized cross-origin credentialed requests to the refresh endpoint.

Security SummaryAI

CVE-2025-34291 is a chained vulnerability in Langflow versions up to and including 1.6.9 that enables account takeover and remote code execution. It stems from an overly permissive CORS configuration (allow_origins='*' with allow_credentials=True) paired with a refresh token cookie set as SameSite=None. This combination allows cross-origin requests with credentials from malicious webpages to successfully invoke the refresh endpoint, enabling attackers to steal fresh access and refresh tokens from victim sessions. The vulnerability is rated at CVSS 8.8 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H) and is associated with CWE-346.

The attack requires a victim to visit a malicious webpage controlled by the attacker, which can be delivered via phishing or social engineering. Once loaded, the page performs cross-origin requests including the victim's credentials to the Langflow refresh endpoint, obtaining valid access_token and refresh_token pairs. With these tokens, the attacker gains access to authenticated endpoints, including built-in code-execution functionality, allowing arbitrary code execution and full system compromise. Exploitation requires low privileges (PR:L) as it leverages an existing authenticated user session.

Advisories from Obsidian Security, VulnCheck, and the Langflow GitHub repository detail the issue and recommend mitigation. Security practitioners should consult these sources for patch information, as Langflow versions beyond 1.6.9 address the CORS and cookie misconfigurations.

Langflow is an AI agent workflow platform, making this vulnerability particularly relevant for deployments involving AI/ML workflows where code execution endpoints could expose sensitive models or data. No public evidence of real-world exploitation is noted in available details.

Details

CWE(s)

Affected Products

langflow
langflow
≤ 1.6.9

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1528 Steal Application Access Token Credential Access
Adversaries can steal application access tokens as a means of acquiring credentials to access remote systems and resources.
T1566.002 Spearphishing Link Initial Access
Adversaries may send spearphishing emails with a malicious link in an attempt to gain access to victim systems.
Why these techniques?

CVE enables exploitation of public-facing web application (T1190) via phishing-delivered malicious webpage (T1566.002) to steal application access/refresh tokens (T1528), leading to account takeover and RCE.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References