High severity · published Dec 5, 2025
CVE-2025-34291
Langflow <= 1.6.9 CORS Misconfiguration to Token Hijack & RCE
In wildKEV
8.8
CVSS
92.8%
EPSS
Yes
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)92.8% · higher than 100% of CVEs
Exploited in the wildYes
CISA KEVListed May 21, 2026
Federal remediation dueJun 4, 2026
Ransomware campaign useNot known
Affected products
Which versions
LA
Langflow · Langflow
through 1.6.9 · source: vendor, NVD, KEV
In the news
VulnerabilityCritical
U.S. CISA adds Trend Micro Apex One and Langflow to its Known Exploited Vulnerabilities catalog
U.S. Cybersecurity and Infrastructure Security Agency (CISA) adds Trend Micro Apex One and Langflow flaws to its Known Exploited Vulnerabilities catalog. The U.S. Cybersecurity and Infrastructure Security Agency (CISA)&#160;added Windows Shell and ConnectWise ScreenConnect flaws to its Known Exploited Vulnerabilities (KEV) catalog. Below are the flaws added to the catalog: CVE-2025-34291&#160;(CVSS score of 9.4) is [&#8230;]
May 22, 2026·Security Affairs
VulnerabilityCritical
CISA Adds Exploited Langflow and Trend Micro Apex One Vulnerabilities to KEV
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Thursday added two security flaws impacting Langflow and Trend Micro Apex One to its Known Exploited Vulnerabilities (KEV) catalog, citing evidence of active exploitation. The vulnerabilities in question are listed below - CVE-2025-34291 (CVSS score: 9.4) - An origin validation error vulnerability in Langflow that could
May 22, 2026·The Hacker News
VulnerabilityHigh
CISA Adds Two Known Exploited Vulnerabilities to Catalog
CISA has added two new vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog , based on evidence of active exploitation. CVE-2025-34291 Langflow Origin Validation Error Vulnerability CVE-2026-34926 Trend Micro Apex One (On-Premise) Directory Traversal Vulnerability These types of vulnerabilities are frequent attack vectors for malicious cyber actors and pose significant risks to the federal enterprise. Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities established the KEV Catalog as a living list of known Common Vulnerabilities and Exposures (CVEs) that carry significant risk to the federal enterprise. BOD 22-01 requires Federal Civilian Executive Branch (FCEB) agencies to remediate identified vulnerabilities by the due date to protect FCEB networks against active threats. See the BOD 22-01 Fact Sheet for more information. Although BOD 22-01 only applies to FCEB agencies, CISA strongly urges all organizations to reduce their exposure to cyberattacks by prioritizing timely remediation of KEV Catalog vulnerabilities as part of their vulnerability management practice. CISA will continue to add vulnerabilities to the catalog that meet the specified criteria .&nbsp;
May 21, 2026·CISA Advisories
ThreatIntelHigh
[CISA KEV] CVE-2025-34291: Langflow Langflow - Langflow Origin Validation Error Vulnerability
Langflow contains an origin validation error vulnerability in which an overly permissive CORS configuration 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. This could allow the attacker to execute arbitrary code and achieve full system compromise via obtained tokens that permit access to authenticated endpoints.
LALangflowCVE-2025-34291
May 21, 2026·CISA KEV
Affected product
LA
Langflow
Langflow
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