Known exploited vulnerability
CVE-2025-34291
The short answer
CVE-2025-34291 affects Langflow Langflow and is rated critical (CVSS 9.4). CISA added it to the Known Exploited Vulnerabilities catalog on 2026-05-21: attackers are using it, so patch it first. Fixed versions are published for langflow (1.7.0).
What it is
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.
Weakness: CWE-346.
Severity
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/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
Exploited (CISA KEV)
Yes, since May 21, 2026
Federal due date Jun 4, 2026
EPSS, next 30 days
93%
Higher than 100% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- Passive
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
What CISA says to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Affected packages and fixed versions
| Package | Ecosystem | Fixed in | Advisory |
|---|---|---|---|
| langflow | PyPI | 1.7.0 | GHSA-577h-p2hh-v4mv |
Is it in your code? Drop your lockfile into the free vulnerability check, or let vulnerability watch check your repository every day and open the upgrade as a pull request.
Affected products
Langflow. NVD's record lists the exact affected versions.
References
- github.com/langflow-ai/langflow Product
- www.obsidiansecurity.com/blog/cve-2025-34291-critical-account-takeover-and-rce-vulnerability-in-the-langflow-ai-agent-workflow-platform ExploitMitigationThird Party Advisory
- www.vulncheck.com/advisories/langflow-cors-misconfiguration-to-token-hijack-and-rce Third Party Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-34291 US Government Resource
- www.crowdsec.net/vulntracking-report/cve-2025-34291 Third Party Advisory
Questions
Is CVE-2025-34291 being exploited?
Yes. CISA added CVE-2025-34291 to its Known Exploited Vulnerabilities catalog on 2026-05-21, with a federal remediation due date of 2026-06-04.
How do I fix CVE-2025-34291?
Upgrade to a fixed version: langflow (PyPI) 1.7.0. CISA's 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.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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