9.4

CVE-2025-34291: Langflow Origin Validation Error Vulnerability

CVSS: 9.4v4.0CriticalKEVAnalyzed
AliasesGHSA-577h-p2hh-v4mvPYSEC-2025-78
Published 05-12-2025Last modified 08-10-2026
Open JSON

Vulnerability summary

CVE-2025-34291 is a critical (CVSS 9.4) Origin Validation Error vulnerability in Langflow. It is known to be exploited: CISA lists it, first on 21-05-2026. EPSS estimates a 92.81% chance of exploitation in the next 30 days, higher than 99.8% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
85/100
0100
Critical · default modelHow is this calculated?
CVSS score
9.4/10
010
Critical · v4.0 (CVE.org)
EPSS score
92.81%
0%100%
Critical · +9.18 pp in 30 days
KEVListedCISA
RansomwareNone recordedNo known use recorded
Public exploits1reference

Timeline

  1. 05-12-2025
    PublishedVulnerability first disclosed.
  2. 21-05-2026
    Added to CISA KEVLangflow Origin Validation Error Vulnerability
  3. 04-06-2026
    CISA remediation dueApply mitigations per vendor instructions.
  4. 08-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

92.81%

Chance of exploitation in the next 30 days

Percentile

100%

Versus all other CVEs

30-day change

+9.18 pp

From 83.63% on 21-09-2026

21-09-202621-10-2026
EPSS score
92.81%

Known exploited

Compare KEV catalogs
CISA KEVListed
Added
21-05-2026
Federal due date
04-06-2026

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. github.com/langflow-ai/langflow/releases/tag/v1.9.3 github.com/langflow-ai/langflow/issues/11465 nvd.nist.gov/vuln/detail/CVE-2025-34291

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (obsidiansecurity.com)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Langflow1 product
PyPI1 product
  • langflow< 1.7.0

2 vendors · 2 products

References

12 links
Show all 12 references