Cyber Resilience

CVE-2025-34291

Langflow ≤ 1.6.9

CISA KEVActive ExploitationPublic PoC
Published
05 December 2025
Modified
14 July 2026
KEV Added
21 May 2026
Patch / advisory
CVSS Score v4 9.4
Click a component to see what it means
Raw vectorCVSS: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
EPSS Score 0.84 99.7th percentile
Risk Priority 100 floored blend · peak EPSS

Summary

CVE-2025-34291 is a critical-severity Origin Validation Error (CWE-346) vulnerability in Langflow Langflow. Its CVSS base score is 9.4 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique DHCP Spoofing (T1557.003); ranked in the top 0.3% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

This vulnerability is AI-related — categorised as LLM Application Platforms; in the Supply Chain and Deployment risk domain.

The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and IA-3 (Device Identification and Authentication) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

Langflow versions up to and including 1.6.9 contain a chained vulnerability stemming from an overly permissive CORS policy that sets allow_origins to wildcard while also enabling allow_credentials, paired with a refresh token cookie configured as SameSite=None. This combination is tracked under CWE-346 and carries a CVSS 4.0 score of 9.4.

An attacker who can lure a victim to a malicious webpage can issue cross-origin requests that include credentials, invoke the refresh endpoint, and obtain fresh access and refresh token pairs. With those tokens the attacker gains access to authenticated endpoints, including Langflow’s built-in code-execution functionality, resulting in arbitrary code execution and full system compromise.

The vulnerability appears in the CISA Known Exploited Vulnerabilities catalog and has been analyzed in public reports from Obsidian Security and VulnCheck. Its EPSS score has remained elevated, reaching a peak of 0.3538 and currently sitting at 0.3275, indicating sustained exploitation interest since disclosure. Langflow is an AI-agent workflow platform, making the remote-code-execution path particularly concerning for organizations running unpatched instances.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
KEV Date Added
21 May 2026

AI Security AnalysisAI

AI Category
LLM Application Platforms
Risk Domain
Supply Chain and Deployment
OWASP Top 10 for LLMs 2025
None mapped
Classification Reason
Matched keywords: langflow

Related Threats

MITRE ATT&CK Enterprise Techniques

T1557.003 DHCP Spoofing Credential Access
Adversaries may redirect network traffic to adversary-owned systems by spoofing Dynamic Host Configuration Protocol (DHCP) traffic and acting as a malicious DHCP server on the victim network.
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
T1557.001 Name Resolution Poisoning and SMB Relay Credential Access
By responding to LLMNR/NBT-NS/mDNS network traffic, adversaries may spoof an authoritative source for name resolution to force communication with an adversary controlled system.
T1557.002 ARP Cache Poisoning Credential Access
Adversaries may poison Address Resolution Protocol (ARP) caches to position themselves between the communication of two or more networked devices.
T1557.004 Evil Twin Credential Access
Adversaries may host seemingly genuine Wi-Fi access points to deceive users into connecting to malicious networks as a way of supporting follow-on behaviors such as [Network Sniffing](https://attack.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-55255Same product: Langflow Langflowboth on KEV
CVE-2025-3248Same product: Langflow Langflowboth on KEV
CVE-2026-33017Same product: Langflow Langflowboth on KEV
CVE-2026-0770Same product: Langflow Langflowboth on KEV
CVE-2026-9198Same product: Langflow Langflowboth on KEV
CVE-2026-42867Same product: Langflow Langflow
CVE-2026-6542Same product: Langflow Langflow
CVE-2026-33053Same product: Langflow Langflow
CVE-2026-10564Same product: Langflow Langflow
CVE-2026-33497Same product: Langflow Langflow

Affected Assets

langflow
langflow
≤ 1.6.9

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 3 hardening rules · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

Information flow enforcement directly requires validating the source of data before allowing transmission or receipt.

Device identification and authentication mandates verifying the source before establishing connections.

Session authenticity mechanisms require validation that communications originate from the expected party.

Boundary protection at interfaces enforces checks on the origin of incoming communications.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-03 mostly match
prevents

Authentication directly verifies the source of users/services/hardware, mitigating origin validation failures.

PR.AA-04 mostly match
prevents

Verifying identity assertions enforces origin validation for conveyed claims.

ID.AM-03 partial match
prevents

Documenting authorized flows supports origin validation by defining expected sources.

PR.IR-01 partial match
prevents

Protecting networks from unauthorized access requires origin checks on communication sources.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

mitigates

Network security controls enforce origin validation at network boundaries.

mitigates

Security of network services includes validating the authenticity of service endpoints.

mitigates

Network segregation reduces exposure but does not directly validate origins.

prevents

Application security requirements explicitly call for origin validation of inputs and communications.

prevents

Secure architecture principles encourage origin checks but do not mandate them.

prevents

Secure coding practices include implementing proper origin validation to prevent spoofing.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (3 rules)
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-346
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-346
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-346

References