Langflow <= 1.6.9 CORS Misconfiguration to Token Hijack & RCE

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2025-34291
StatePUBLISHED
AssignerVulnCheck
Source PriorityCVE Program / NVD first with legacy fallback
Published2025-12-05 23:15:47 UTC
Updated2026-07-14 23:17:22 UTC
DescriptionLangflow 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.

Risk And Classification

Primary CVSS: v4.0 9.4 CRITICAL from [email protected]

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.788900000 probability, percentile 0.995540000 (date 2026-07-22)

CISA KEV: Listed on 2026-05-21; due 2026-06-04; ransomware use Unknown

Problem Types: CWE-346 | CWE-346 CWE-346 Origin Validation Error

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary9.4CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/C...
4.0CNACVSS9.4CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
3.1[email protected]Primary8.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
Passive
Confidentiality
High
Integrity
High
Availability
High
Sub Conf.
High
Sub Integrity
High
Sub Availability
High

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

CISA Known Exploited Vulnerability

VendorLangflow
ProductLangflow
NameLangflow Origin Validation Error Vulnerability
Required ActionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
NotesThis 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

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Langflow Langflow All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Langflow Langflow affected 1.6.9 semver Not specified

References

ReferenceSourceLinkTags
www.obsidiansecurity.com/blog/cve-2025-34291-critical-account-takeover-and-rce-vulnera... [email protected] www.obsidiansecurity.com Exploit, Mitigation, Third Party Advisory
www.crowdsec.net/vulntracking-report/cve-2025-34291 134c704f-9b21-4f2e-91b3-4a467353bcc0 www.crowdsec.net Third Party Advisory
www.vulncheck.com/advisories/langflow-cors-misconfiguration-to-token-hijack-and... [email protected] www.vulncheck.com Third Party Advisory
github.com/langflow-ai/langflow [email protected] github.com Product
www.cisa.gov/known-exploited-vulnerabilities-catalog 134c704f-9b21-4f2e-91b3-4a467353bcc0 www.cisa.gov US Government Resource
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
CISA Known Exploited Vulnerabilities catalog CISA www.cisa.gov kev

Vendor Comments And Credit

Discovery Credit

CNA: Fenix Qiao (aka 13ph03nix) from Obsidian Security (en)

CNA: Shuyang Wang from Obsidian Security (en)

Additional Advisory Data

SourceTimeEvent
ADP2026-05-21T00:00:00.000ZCVE-2025-34291 added to CISA KEV

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