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CVE-2025-34291

8.8, high Known exploited

Langflow Origin Validation Error Vulnerability

NVD (opens in a new tab) CVE.org (opens in a new tab) CISA KEV catalogue (opens in a new tab)
CVSS
8.8, high high CVSS v3.1
EPSS, next 30 days
93% higher than 99.8% of scored CVEs
Exploitation
Confirmed in the wild
Published
5 Dec 202510 months ago

Known exploited

CISA added this to the Known Exploited Vulnerabilities Catalog on 21 May 2026. US federal agencies had to remediate by 4 Jun 2026, a deadline that has passed.

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.

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.

Details

Vendor
Langflow
Product
Langflow
Weakness
CWE-346 (opens in a new tab)
Status
Analyzed
Updated
15 Oct 2026
Assigner
disclosure@vulncheck.com

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References 5

Exploit code 1

Advisories 2

Other references 2

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other Langflow CVEs

Every Langflow CVE we hold

Same vendor in what we hold, not a known link between the flaws.

  • CVE-2026-55255 Langflow Authorization Bypass Through User-Controlled Key Vulnerability KEV EPSS 0.9% 8.4, high
  • CVE-2026-33017 Langflow Code Injection Vulnerability KEV EPSS 25% 9.8, critical
  • CVE-2026-0770 Langflow Inclusion of Functionality from Untrusted Control Sphere Vulnerability KEV EPSS 63% 9.8, critical
  • CVE-2025-3248 Langflow Missing Authentication Vulnerability KEV EPSS 100% 9.8, critical

Beyond this page

Is CVE-2025-34291 in your network?

This page tells you how dangerous CVE-2025-34291 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

CVE-2025-34291 is in the CISA catalogue of exploited vulnerabilities: attackers are already exploiting it.

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  • EXYS7950 KONDRA

    Detect it if it's exploited

    Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.

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Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 17 Oct 2026, not the live upstream state.