Exploited vulnerabilities / CVE-2025-34291
Confirmed exploited · remote code execution · LangflowCVE-2025-34291
Langflow remote code execution, confirmed exploited in the wild.
Langflow contains an origin validation error vulnerability in which an overly permissive CORS configuration 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. This could allow the attacker to execute arbitrary code and achieve full system compromise via obtained tokens that permit access to authenticated endpoints.
| CISA's name for it | Langflow Origin Validation Error Vulnerability |
|---|---|
| Vendor and product | Langflow · Langflow |
| Type | remote code execution · CWE-346 |
| Exploited | Confirmed by CISA listed 21 May 2026 |
| Likelihood | one of the most likely to be exploited of every vulnerability tracked |
| Deadline | 4 June 2026 · already passed |
| Used in ransomware | Not reported |
| Advisories | github.com ↗ · github.com ↗ · github.com ↗ · nvd.nist.gov ↗ |
Three steps, in this order
Patch to the fixed version the vendor names, today if the product faces the internet.
Until it is patched, take the affected service off the internet or put it behind a VPN or allow-list.
Look for signs it was already used: new accounts, web shells, unexpected processes and outbound connections since the date it was listed.
| 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. |
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Know before someone else finds it
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CVE-2025-34291 in short
Is CVE-2025-34291 being exploited?
Yes. CISA added CVE-2025-34291 to its Known Exploited Vulnerabilities catalogue on 21 May 2026, which it does only on evidence of exploitation in the wild.
What is the CISA deadline for CVE-2025-34291?
US federal agencies must remediate it by 4 June 2026. Everyone else should treat that date as the latest safe point to patch an internet-facing system.
How likely is CVE-2025-34291 to be exploited in the next 30 days?
FIRST's Exploit Prediction Scoring System gives it 93%, the 99th percentile of every CVE it scores.
How do I fix CVE-2025-34291?
Patch to the fixed version the vendor names, today if the product faces the internet. Until it is patched, take the affected service off the internet or put it behind a VPN or allow-list. Look for signs it was already used: new accounts, web shells, unexpected processes and outbound connections since the date it was listed.
Other Langflow vulnerabilities being exploited
| CVE | Product | Type | Listed |
|---|---|---|---|
| CVE-2026-0770 | Langflow | remote code execution | 21 July 2026 |
| CVE-2026-55255 | Langflow | exploited vulnerability | 7 July 2026 |
| CVE-2026-33017 | Langflow | exploited vulnerability | 25 March 2026 |
Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.