VulnerabilityPublished 1 Jul 2026

CVE-2026-50143: Actors mcp server · Apify Model Context Protocol (MCP) server: Actor MCP path authority injection leaks Apify token

Affects @apify/actors-mcp-serverSource GCVE Database

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Authoritative record:CVE-2026-50143· High 8.1

Not known to be exploited · CVSS 8.1 High : upgrade to 0.10.11 soon.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

8.1High

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.10.11

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: High
Integrity: High
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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
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: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 18 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CISA SSVC: proof of concept public
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

CVE ID reserved
by GitHub, Inc.
3 Jun 202618:49 UTC, 76 days before disclosure
CVE published
on cve.org
18 Aug 202617:51 UTC, t = 0
CISA SSVC assessment
proof of concept public
18 Aug 202619:30 UTC, 2 hours after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 29 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 @apify/actors-mcp-server to 0.10.11.

Affected software

Product	Affected	Fixed in
npm@apify/actors-mcp-server	Affected <0.10.11	Fixed in 0.10.11

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

An official patch is available that fixes this vulnerability. Users should upgrade @apify/actors-mcp-server to version 0.10.11 or later. Until patched, avoid running untrusted Actors or those with unverified `webServerMcpPath` values. The vendor advisory confirms a fix is available; apply it promptly to prevent token leakage.

Description

The Apify MCP server enables AI agents to extract data from websites using ready-made scrapers, crawlers, and automation tools available on the Apify Store. Prior to 0.10.11, getActorMCPServerURL in src/mcp/actors.ts concatenates the trusted Actor standby URL with the attacker-controlled webServerMcpPath from an Actor definition without verifying the resulting origin, allowing a malicious Actor publisher to use a userinfo-style authority value to redirect connectMCPClient to a third-party host. The call-actor, fetch-actor-details, and actor-mcp tool-loading paths pass this URL to transports in src/mcp/client.ts that attach the victim Authorization bearer token, exposing the Apify API token and enabling access to Actors, stored data, and billable compute. A victim must invoke or inspect the attacker-controlled Actor. This issue is fixed in version 0.10.11.

Impact

An attacker can exfiltrate the victim's Apify API token by publishing a malicious Actor with a crafted `webServerMcpPath`. This token leakage can lead to unauthorized access to the victim's Apify account and resources. The vulnerability does not affect availability but compromises confidentiality and integrity of the victim's credentials.

Summary

@apify/actors-mcp-server versions prior to 0.10.11 construct Actor standby URLs by concatenating a trusted base URL with the `webServerMcpPath` field from an Actor definition without validating that the path is relative or free of authority injection characters such as '@'. An attacker publishing a malicious Actor with a crafted `webServerMcpPath` (e.g., '@attacker.example/mcp') causes the resulting URL to be interpreted with the attacker’s host as authority, per RFC 3986 and WHATWG URL parsing. The MCP client then attaches the victim's Apify API token as a Bearer token in the Authorization header to requests sent to the attacker’s server, resulting in token exfiltration. The vulnerability is triggered through multiple code paths that fetch the Actor definition and connect the MCP client, with no origin checks performed before sending the token. A proof-of-concept demonstrates the attack in a network-isolated Docker environment.

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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Description

AI analysisMachine-generated, updated 19 Aug 2026, 11:13 UTC

WeaknessesCWE-918

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