Exploited CVEs / Langflow / CVE-2025-34291

CVE-2025-34291

Langflow Origin Validation Error Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2026-06-04 (that deadline has passed); treat that date as the outer bound for your own environment. Check the vendor security advisory for the fix.

Risk summary

HighCISA KEV

8.8

CVSS v3 base

84%

EPSS exploit probability

High

Severity

2026-05-21

Added to KEV

2026-06-04 (past due)

CISA due date

Actively exploited Langflow vulnerability, High severity, CVSS v3 8.8. Added to the CISA KEV catalog 2026-05-21.

Senserva AI read on CVE-2025-34291 CISA required action Official fix for CVE-2025-34291 Admin questions

Senserva AI Opinion for CVE-2025-34291

Langflow's overly permissive CORS configuration, combined with a refresh token cookie set to SameSite=None, lets a malicious webpage make credentialed cross-origin calls into the server from a victim's browser. It is rated High Severity at CVSS 8.8 with a 79% EPSS score, confirmed exploited since 2026-05-21. Together with the code injection flaw also in the KEV catalog, it gives attackers both a browser-borne and a direct route into Langflow deployments.

Do this: Upgrade Langflow and tighten its CORS and cookie settings so browser sessions cannot be ridden from arbitrary sites.

AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2025-34291

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I run IT security. Facts for CVE-2025-34291, an actively exploited vulnerability (source: https://senserva.com/cve/CVE-2025-34291.html, data from CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2025-34291: Langflow Origin Validation Error Vulnerability
- Affected: Langflow
- Severity: High, CVSS v3 8.8; EPSS 30-day exploitation probability 84%
- Added to CISA KEV: 2026-05-21; federal remediation due 2026-06-04
- Ransomware-linked: no
- CISA 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.
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) The fastest safe path to remediation. 4) How to check whether my environment is exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Patch now

Exploited in the wild: confirmed by the CISA KEV catalog, not predicted.

No vendor fix is mapped yet. This page refreshes daily and will name the patch the day one is published.

Do this now: Federal remediation deadline 2026-06-04; treat it as your outer bound. Patch now and verify deployment on every exposed device.

Updated August 23, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Full tracking and change history for CVE-2025-34291

Published: 2026-05-21
Last revised: 2026-05-21
Changes tracked: 1

Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.

Senserva Watchevery change we have recorded for this one

What changed, and when

Drawn by Senserva Vivid from the Senserva change record. Hover any point for its date and value.

2026-05-21 added to the CISA KEV catalog by CISA
2026-07-17 CVSS 0.0 to 8.8; EPSS first scored at 78.9%
2026-07-24 EPSS 78.9% to 83.6%
2026-08-02 EPSS 83.6% to 83.8%

Recorded by Senserva on the dates shown, from CISA KEV and FIRST EPSS. This is what moved and when, which neither the vendor advisory nor NVD publishes.

CISA required action

Federal (BOD 22-01) remediation due date: 2026-06-04 (past due).

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Official fix for CVE-2025-34291

Check the vendor's security advisory channel for the patched Langflow versions and workarounds.

CISA KEV entry

Common questions about CVE-2025-34291

Is CVE-2025-34291 actively exploited?

Yes. CVE-2025-34291 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2026-05-21, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 84%.

What is the CISA deadline and required action for CVE-2025-34291?

CISA set the federal (BOD 22-01) remediation due date at 2026-06-04, which has passed; treat any unremediated system as overdue. The verbatim 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.

What fixes CVE-2025-34291?

Check the vendor's security advisory for the patched Langflow versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.

Can I ask my own AI about CVE-2025-34291?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2025-34291's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).

Scope and sources

More exploited Langflow CVEs: CVE-2026-0770 CVE-2026-55255 CVE-2026-33017 CVE-2025-3248
All Langflow exploited CVEs on one page: Langflow vulnerabilities actively exploited.
Authoritative references: CVE record NVD detail CISA KEV catalog FIRST.org EPSS

Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.