VulnerabilityPublished 7 May 2026

CVE-2026-42449: czlonkowski n8n-mcp · Server-Side Request Forgery (SSRF)

Affects czlonkowski n8n-mcpSource CVE Database V5

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Not known to be exploited · CVSS 8.5 High : upgrade to 2.47.14 soon.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

8.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.47.14

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Changed
Confidentiality: High
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 7 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade n8n-mcp and czlonkowski/n8n-mcp to 2.47.14.

Affected software

Product	Affected	Fixed in
czlonkowskin8n-mcp	Affected >=2.47.4 <2.47.14	Fixed in 2.47.14
GitHubczlonkowski/n8n-mcp`pkg:github/czlonkowski/n8n-mcp`Other threats	Affected >=2.47.4 <2.47.14	Fixed in 2.47.14

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AI-suggested

A fixed version 2.47.14 of n8n-mcp is available and should be applied to remediate this vulnerability. If immediate upgrade is not possible, users should validate URLs before passing them to the SDK to ensure they do not point to internal or sensitive endpoints. Additionally, restricting egress network traffic to prevent unauthorized outbound requests and rejecting user-controlled n8nApiUrl values can mitigate exploitation risk. The first-party HTTP server deployment is less affected due to an additional asynchronous validator, but upgrading is still recommended.

Description

### Impact In the SDK embedder path (`N8NDocumentationMCPServer` constructor, `getN8nApiClient()`, and `validateInstanceContext()`), the synchronous URL validator in `SSRFProtection.validateUrlSync()` had no IPv6 checks. IPv4-mapped IPv6 addresses such as `http://[::ffff:169.254.169.254]` bypassed the cloud-metadata, localhost, and private-IP range checks. An attacker able to supply an `n8nApiUrl` value could cause the server to issue HTTP requests to cloud metadata endpoints (AWS IMDS, GCP, Azure, Alibaba, Oracle), RFC1918 private networks, or localhost services. Response bodies are returned to the caller (non-blind SSRF), and the `n8nApiKey` is forwarded in the `x-n8n-api-key` header to the attacker-controlled target. The first-party HTTP server deployment was not primarily affected — it has a second async validator (`validateWebhookUrl`) that catches IPv6 addresses. Impact category: **CWE-918** (Server-Side Request Forgery). ### Affected Deployments embedding n8n-mcp as an SDK using `N8NDocumentationMCPServer` or `N8NMCPEngine` with user-supplied `InstanceContext` on versions **v2.47.4 through v2.47.13**. ### Patched **v2.47.14** and later. - npm: `npx n8n-mcp@latest` (or pin to `>= 2.47.14`) - Docker: `docker pull ghcr.io/czlonkowski/n8n-mcp:latest` ### Workarounds If developers cannot upgrade immediately: - **Validate URLs before passing to the SDK** — reject any `n8nApiUrl` whose hostname is an IP literal (bracketed IPv6 or dotted IPv4) before calling `N8NDocumentationMCPServer` / `getN8nApiClient()`. Accept only URLs with DNS-resolvable hostnames. - **Restrict egress at the network layer** — block outbound traffic from the n8n-mcp process to RFC1918 ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16), link-local `169.254.0.0/16`, and cloud metadata endpoints. Defense-in-depth against this class of issue and recommended even after upgrading. - **Do not accept user-controlled `n8nApiUrl` values** — if the project's integration derives the URL from internal configuration only, this vulnerability is not reachable. Upgrading to v2.47.14 is still strongly recommended. ### Credit Reported by @manthanghasadiya.

Impact

An attacker with the ability to supply the n8nApiUrl parameter can exploit this SSRF vulnerability to make the server issue HTTP requests to internal services such as cloud metadata endpoints, localhost, and private IP ranges. The server returns the response bodies to the attacker, enabling information disclosure (non-blind SSRF). Additionally, the n8nApiKey is forwarded in the x-n8n-api-key header to the attacker-controlled target, which could lead to further unauthorized access or privilege escalation. This vulnerability has a CVSS score of 8.5 (high severity), indicating a significant risk of confidentiality impact and partial integrity impact without availability impact.

Summary

The n8n-mcp SDK versions 2.47.4 to 2.47.13 contain an SSRF vulnerability due to insufficient IPv6 validation in the synchronous URL validator (SSRFProtection.validateUrlSync). Specifically, IPv4-mapped IPv6 addresses such as http://[::ffff:169.254.169.254] bypass checks designed to block requests to cloud metadata services, localhost, and private IP ranges. This allows an attacker who can supply the n8nApiUrl parameter to induce the server to send HTTP requests to these protected endpoints. The server returns the response body to the attacker and forwards the n8nApiKey in the x-n8n-api-key header, potentially exposing sensitive information. The vulnerability affects projects embedding n8n-mcp as an SDK with user-supplied InstanceContext. The first-party HTTP server deployment is less affected due to an additional asynchronous validator that blocks IPv6 addresses. The vulnerability is resolved in version 2.47.14. Until upgrading, users can mitigate risk by validating URLs before passing them to the SDK, restricting egress traffic at the network layer, and rejecting user-controlled n8nApiUrl values.

CWE-918Server-Side Request Forgery (opens in a new tab)
Base weaknessCWE Top 25 (2025): #22OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
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.
Implementation · Operation
If there is a known list of applications, IP, hostname, and/or domains to which the product is allowed to communicate, then use allowlists to ensure that outgoing requests are restricted to these known entities. The allowlists could be in the application code or possibly enforced by firewalls or network segmentation.
Implementation · Operation
If the product is expected to be able to connect to arbitrary IP addresses or domains, consider using a denylist that includes private network addresses, internal domain names, etc. The denylist could be in the application code or possibly enforced by firewalls or network segmentation.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
OWASP Cheat Sheets
Server Side Request Forgery Prevention (opens in a new tab)
Unvalidated Redirects and Forwards (opens in a new tab)
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.6.1 (opens in a new tab)
V5.2.6 (opens in a new tab)
Attack patterns
Server Side Request Forgery (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 15 May 2026, 10:59 UTC

WeaknessesCWE-918

Technical details

References

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