CVE-2025-34291
Langflow — Langflow Origin Validation Error Vulnerability
Langflow · CWE-346 · in CISA KEV since 2026-05-21
EVRS 87 of 100 Immediate
Out-of-Band / Urgent Remediation
Rank 293 of 2,962 tracked
Why it scores 87
Evidence available: 6 of 7 signalsListed in the CISA KEV catalog, and an EPSS probability of 0.928.
- CISA KEVApplied
- RansomwareDid not apply
- Vendor exploitationDid not apply
- EPSSApplied
- Microsoft Exploitability IndexNot applicable
- Pre-patch disclosureNo data
- KEV recencyDid not apply
- CVSSApplied
The band answers “how soon”, not “how bad”. No data for: Pre-patch disclosure. Why some signals show no data
Fix
Patch or fixed version identifiedCISA required action
- This 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
- github.com/…/v1.9.3
- github.com/…/11465#event-25774545848
- nvd.nist.gov/…/CVE-2025-34291
Fixed in
- langflow
1.7.0
Affected versions
- langflow (pip)
affected <= 1.6.9, fixed in 1.7.0
Remediation
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Fixed versions from NVD and GitHub. Affected packages also in GitHub Advisory GHSA-577h-p2hh-v4mv (CC BY 4.0).
Evidence
Each value with its source| Measure | Value | Source |
|---|---|---|
| CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. | 9.4 | NVD |
| FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. | 0.928 (99.83rd pctl) | FIRST EPSS |
| Actively exploitedWhether a source of record has confirmed attacks using it in the wild. | Confirmed | CISA KEV |
| Ransomware campaign useWhether CISA has seen ransomware operators use it. | Unknown or none | CISA KEV |
| CISA remediation deadlineThe date US federal agencies must have fixed or mitigated it. | 2026-06-04 · CISA federal deadline · Overdue by 5 months | CISA KEV |
| Public exploit moduleA module existing is not the same as active exploitation. | None known | Metasploit |
| EUVD cross-referenceENISA's record: CVSS 9.4 (v4.0), assigned by VulnCheck. | Listed | ENISA EUVD |
Description
NVDLangflow 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.
What CISA says to do