What it is
CVE-2025-34291 is an unauthenticated Langflow <= 1.6.9 CORS Misconfiguration to Token Hijack & RCE. Langflow versions up to and including 1.6.9 contain a chained vulnerability that enables account takeover and remote...
Vulnerability report
Exploited in the wild
Confirmed confidence
In CISA KEV
CVE-2025-34291
Langflow <= 1.6.9 CORS Misconfiguration to Token Hijack & RCE
Langflow / Langflow · 0 to <= 1.6.9
- Severity
- CVSS 9.4 · Critical
- Confidence
- Confirmed
- Exploit status
- Exploited in the wild
- EPSS
- 83.8%
- First observed
- —
- Last observed
- —
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.
Who is affected?
Langflow / Langflow 0 to <= 1.6.9.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
Langflow <= 1.6.9 CORS Misconfiguration to Token Hijack & RCE
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.
Vendor
Product
Affected
Status
Langflow
Langflow
Through 1.6.9
Affected
- Published
- 05 Dec 2025
- Exploitation Reported
- 01 Jun 2026
- Attack vector
- Remote
- Complexity
- Low
- Privileges
- None
- User interaction
- —
Tags
nuclei_scanner
cisa
CVE References
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2025-34291
- Third-Party Advisory — vulncheck.com vulncheck.com · Third-Party Advisory https://www.vulncheck.com/advisories/langflow-cors-misconfiguration-t...
- Exploit — obsidiansecurity.com obsidiansecurity.com · Exploit https://www.obsidiansecurity.com/blog/cve-2025-34291-critical-account...
- GitHub — langflow-ai/langflow github.com · Product https://github.com/langflow-ai/langflow
Exploitation evidence
Why KEV Intelligence marks this CVE as exploited
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploited in the wild
CVE
Independent exploitation attestation added to the KEV Intelligence record.
Proof of concept available
Nuclei Templates
Public scanner or PoC coverage increases practical exploitability.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CVE First | 2026-06-01 13:29 UTC |
| CISA | 2026-06-02 14:00 UTC |
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Observed signals
- Request targets
- 0
- User-Agents
- 0
Raw values available in Pro and Enterprise.
Scanner coverage
Nuclei template detected 01 Jun 2026.
View Nuclei template (opens in new tab)Virtual patch status
No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →Scanner Artifacts
Scanner and exploit-framework references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-34291.yaml | 01 Jun 2026 |
Risk and context
Severity, weaknesses, and research context
CVSS v4.0
9.4
Critical
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
EPSS
83.8%
Weaknesses
All CVSS Scores
CVSS v4.0
9.4
Critical
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
CVSS v3.1
8.8
High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
Langflow AI <= 1.6.9 - CORS Misconfiguration
nuclei · Created Unknown
Timeline
From disclosure to observed exploitation
-
Public PoC available
Public proof-of-concept code published
-
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
Nuclei template available
Scanner coverage available
-
Added to KEV Intelligence KEV Feed
High-confidence, third-party attested exploitation
-
CVE published
Vulnerability disclosed publicly
-
CVE ID reserved
Identifier reserved by the CNA
Pro API
Automate this intelligence
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
- Evidence confidence and provenance
- First-party sensor telemetry
- PoC and scanner references
- Affected versions and enrichment
- Automation-ready JSON delivery
GET /api/v2/pro/kevs/CVE-2025-34291
Free JSON includes basic KEV fields{
"cve_id": "CVE-2025-34291",
"confidence": "Confirmed",
"cvss_score": 9.4,
"cvss_estimated": false,
"epss_score": 0.83844,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}Early warning alerts
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