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Full vulnerability report · 2026
CVE-2026-67620High confidence

Flowise 3.1.4 SSRF via fetch-links Endpoint Incomplete Deny-List

FlowiseAI · Flowise

6.3MediumCVSS 4.0
Recommended action
Within 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Mitigation available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:High, raised one band.upgradedsince 14 Aug 2026

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • EPSS is 0.46% for the current model date.

Compensating controls

  • Apply the linked authoritative mitigation while planning the permanent fix.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs FlowiseAI Flowise and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 30 daysRemediation target: Within 180 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-54793

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Mitigation available
01

What, why and how

Flowise through 3.1.4 contains a server-side request forgery vulnerability in the SSRF guard implemented in httpSecurity.ts, where the DEFAULT_DENY_LIST omits the Oracle Cloud Infrastructure metadata endpoint 192.0.0.192 and the Alibaba Cloud metadata endpoint 100.100.100.200, allowing authenticated attackers to force the server to issue arbitrary GET requests to cloud instance metadata services. Attackers can send requests to the fetch-links API endpoint with a crafted URL parameter, bypassing deny-list validation including redirect-based bypasses, to reach instance metadata services and expose instance identity data and role credentials on Oracle Cloud Infrastructure or Alibaba Cloud deployments, with unauthenticated access possible when URL-fetching nodes exist in public chatflows.

What

Flowise through 3.1.4 contains a server-side request forgery vulnerability in the SSRF guard implemented in httpSecurity.ts, where the DEFAULT_DENY_LIST omits the Oracle Cloud Infrastructure metadata endpoint 192.0.0.192 and the Alibaba Cloud metadata endpoint 100.100.100.200, allowing authenticated attackers to force the server to issue arbitrary GET requests to cloud instance metadata services. Attackers can send requests to the fetch-links API endpoint with a crafted URL parameter, bypassing deny-list validation including redirect-based bypasses, to reach instance metadata services and expose instance identity data and role credentials on Oracle Cloud Infrastructure or Alibaba Cloud deployments, with unauthenticated access possible when URL-fetching nodes exist in public chatflows.

Why

The server follows an attacker-influenced destination, allowing requests to systems or services the attacker cannot reach directly.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Flowise through 3.1.4 contains a server-side request forgery vulnerability in the SSRF guard implemented in httpSecurity.ts, where the DEFAULT_DENY_LIST omits the Oracle Cloud Infrastructure metadata endpoint 192.0.0.192 and the Alibaba Cloud metadata endpoint 100.100.100.200, allowing authenticated attackers to force the server to issue arbitrary GET requests to cloud instance metadata services. Attackers can send requests to the fetch-links API endpoint with a crafted URL parameter, bypassing deny-list validation including redirect-based bypasses, to reach instance metadata services and expose instance identity data and role credentials on Oracle Cloud Infrastructure or Alibaba Cloud deployments, with unauthenticated access possible when URL-fetching nodes exist in public chatflows.

Why

The server follows an attacker-influenced destination, allowing requests to systems or services the attacker cannot reach directly.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
a network path → Server-Side Request Forgery (SSRF) → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-918 ↗

CWE-918: Server-Side Request Forgery (SSRF). The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCHighSubsequent-system confidentiality: A successful attack can cause a major loss.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
NetworkCWE-918Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-2719Flowise: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen

Ein entfernter, authentisierter Angreifer kann eine Schwachstelle in Flowise ausnutzen, um Sicherheitsvorkehrungen zu umgehen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260812Security Bulletin 12 Aug 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 12 Aug 2026, published on 12 August 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Mitigation available
Affected
Flowise: ≤ 3.1.4
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Apply the mitigation in the linked authoritative guidance while planning the vendor's permanent fix.
Workaround
A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04

Evidence and provenance

Published 8 Aug 2026 · Last source change 14 Aug 2026, 16:51 UTC · CWE-918 · Server-Side Request Forgery (SSRF)

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-54793
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Vendor guidanceAuthoritative vendor guidance changed: added mitigation: github.com/CVE-2026-67620-poc; added remediation: github.com/CVE-2026-67620-poc.
    Before
    no authoritative guidance recorded
    After
    mitigation: github.com/CVE-2026-67620-poc · remediation: github.com/CVE-2026-67620-poc
    disclosure@vulncheck.com ↗
  2. Remediation statusRemediation status changed from Awaiting fix to Mitigation available.
    Before
    Awaiting fix
    After
    Mitigation available
    disclosure@vulncheck.com ↗
  3. Public exploit evidencePublic exploit evidence changed from Public exploit reference to Public exploit reference.
    Before
    Public exploit reference
    After
    Public exploit reference
    disclosure@vulncheck.com ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Mitigation reference recorded
ENISA EUVD · EUVD-2026-54793↗CISA Vulnrichment SSVC evidence↗Public exploit reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-67620 · cve.blacktree.nl