Langflow <= 1.6.9 CORS Misconfiguration to Token Hijack & RCE
Langflow versions up to and including 1.6.9 are affected, and the default deployment is vulnerable. The product data lists 1.7.0 as the fixed version.
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Listed in CISA KEV
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Actively exploited
- Fix
- Fixed in 1.7.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: active
- Automatable: no
- Technical impact: total
Summary
Langflow, an open-source tool for building AI workflows, is affected in all versions up to and including 1.6.9. A malicious website visited by a logged-in user can steal their session tokens and use them to take over the account and run arbitrary code on the server, potentially gaining full control of the system.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original 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.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: active · Automatable: no · Technical impact: total
- Added to CISA KEV
CISA has evidence of exploitation in the wild
- CISA remediation deadline
Due date for US federal agencies to patch
- Record last updated
- EPSS reached 10%
FIRST estimates at least a 10% chance of exploitation in the next 30 days
Affected versions
- Langflow Langflow
through 1.6.9
- langflowPyPI
fixed in 1.7.0
References 3
obsidiansecurity.com
GitHub · langflow-ai/langflow
Questions about CVE-2025-34291
What does this mean?
The CORS policy accepts any origin with credentials enabled, and the refresh token cookie is set to SameSite=None. Together these let a malicious site obtain fresh access and refresh token pairs for a victim's session, which can then be used on authenticated endpoints, including code execution.Source: vulncheck.com
Am I affected, and how do I check?
Langflow versions up to and including 1.6.9 are affected, and the default deployment is vulnerable. To check a setup, look at the installed Langflow version and at the CORS settings (allow_origins set to '*' with allow_credentials=True) and the refresh token cookie's SameSite attribute.Source: vulncheck.com
What should I do about it?
The product data lists 1.7.0 as the fixed version, so upgrade to Langflow 1.7.0 or later.Source: vulncheck.com
Is it being exploited?
Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2026-05-21, which means it has evidence of attacks. No public exploit code is tracked.Source: cisa.gov, cve.now feed data