VulnerabilityPublished 30 Oct 2026

CVE-2026-62863: gojue moling · Permissive Cross-domain Security Policy with Untrusted Domains

Affects gojue molingSource CVE Database V5

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Not known to be exploited · CVSS 9.6 Critical : upgrade to 0.5.0 as a priority.

Data as of 30 Oct 2026, 21:06 UTC

CVSS 3.1 base score

9.6Critical

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.1	9.6

Patch: Available – fixed in 0.5.0

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

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

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: 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: 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: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 30 Oct 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 moling and gojue/moling to 0.5.0.

Affected software

Product	Affected	Fixed in
gojuemoling	Affected <0.5.0	Fixed in 0.5.0
GitHubgojue/moling`pkg:github/gojue/moling`Other threats	Affected <0.5.0	Fixed in 0.5.0

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

AI-suggested

Upgrade to version 0.5.0 or later, where this vulnerability is fixed. The fix addresses the lack of authentication on the `/sse` and `/message` endpoints and removes the overly permissive cross-origin policy. No other mitigation is required once the update is applied.

Description

CVE-2026-62863 affects the gojue moling MCP server prior to version 0.5.0. When running in SSE mode with the `-l` option, the server's `/sse` and `/message` HTTP endpoints do not authenticate requests, and the mcp-go dependency sets a permissive CORS policy allowing all origins. This allows a malicious web page to open a cross-origin EventSource to `/sse` and read sensitive sessionId information. An attacker can then use the stolen sessionId to send unauthorized MCP tool calls to `/message`, potentially reading or writing local files, executing commands, or performing other actions. The issue is fixed in version 0.5.0.

Impact

An attacker can steal session identifiers via a cross-origin EventSource connection due to the permissive CORS policy and lack of authentication. With the stolen sessionId, the attacker can perform unauthorized MCP tool calls that may lead to local file read/write, command execution, and other potentially harmful actions. This compromises confidentiality, integrity, and availability of the affected system. The CVSS score of 9.6 reflects the critical severity of this remote, unauthenticated attack requiring user interaction.

CWE-942Permissive Cross-domain Security Policy with Untrusted Domains (opens in a new tab)
Variant weaknessOWASP Top 10 A02:2025: Security Misconfiguration (opens in a new tab)
The product uses a web-client protection mechanism such as a Content Security Policy (CSP) or cross-domain policy file, but the policy includes untrusted domains with which the web client is allowed to communicate.
Architecture and Design · Operation · Attack Surface Reduction
Define a restrictive Content Security Policy or cross-domain policy file.
Architecture and Design · Operation · Attack Surface Reduction
Avoid using wildcards in the CSP / cross-domain policy file. Any domain matching the wildcard expression will be implicitly trusted, and can perform two-way interaction with the target server.
Architecture and Design · Operation · Environment Hardening
For Flash, modify crossdomain.xml to use meta-policy options such as 'master-only' or 'none' to reduce the possibility of an attacker planting extraneous cross-domain policy files on a server.
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V1.14.1 (opens in a new tab)
V13.4.2 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-306Missing Authentication for Critical Functionality (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #21OWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
Architecture and Design
Divide the software into anonymous, normal, privileged, and administrative areas. Identify which of these areas require a proven user identity, and use a centralized authentication capability.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
Architecture and Design
Where possible, avoid implementing custom, "grow-your-own" authentication routines and consider using authentication capabilities as provided by the surrounding framework, operating system, or environment.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V1.2.3 (opens in a new tab)
V1.2.2 (opens in a new tab)
V1.2.4 (opens in a new tab)
Attack patterns
Choosing Message Identifier (opens in a new tab)
Force the System to Reset Values (opens in a new tab)
Using Unpublished Interfaces or Functionality (opens in a new tab)
Cross Site Request Forgery (opens in a new tab)
Communication Channel Manipulation (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Oct 2026, 20:52 UTC

WeaknessesCWE-942, CWE-306

Technical details

References

Community reviews

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