CVE-2026-62863
MoLing: unauthenticated SSE and wildcard CORS expose tool sessions
MoLing is a computer-use and browser-use based MCP server. Prior to 0.5.0, when MoLing runs in SSE mode using -l, its /sse and /message HTTP endpoints do not authenticate requests and the mcp-go dependency sets Access-Control-Allow-Origin: *. A malicious web page can open a cross-origin EventSource to /sse, including a loopback listener, and read the endpoint event to obtain sessionId. After a victim running SSE mode visits that page, the attacker can use the disclosed sessionId against /message to send unauthorized MCP tool calls. Depending on the configured tools, those calls can read or write local files, execute commands or perform other actions. Binding only to loopback does not prevent this browser-mediated attack. This issue is fixed in version 0.5.0.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
9.6
MoLing: unauthenticated SSE and wildcard CORS expose tool sessions
MoLing is a computer-use and browser-use based MCP server. Prior to 0.5.0, when MoLing runs in SSE mode using -l, its /sse and /message HTTP endpoints do not authenticate requests and the mcp-go dependency sets Access-Control-Allow-Origin: *. A malicious web page can open a cross-origin EventSource to /sse, including a loopback listener, and read the endpoint event to obtain sessionId. After a victim running SSE mode visits that page, the attacker can use the disclosed sessionId against /message to send unauthorized MCP tool calls. Depending on the configured tools, those calls can read or write local files, execute commands or perform other actions. Binding only to loopback does not prevent this browser-mediated attack. This issue is fixed in version 0.5.0.
- Record
CVE-2026-62863- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L - Weakness
- CWE-942, CWE-306
- Updated
- 2026-11-06
EUVDEUVD-2026-114460
9.6
MoLing is a computer-use and browser-use based MCP server. Prior to 0.5.0, when MoLing runs in SSE mode using -l, its /sse and /message HTTP endpoints do not authenticate requests and the mcp-go dependency sets Access-Control-Allow-Origin: *. A malicious web page can open a cross-origin EventSource to /sse, including a loopback listener, and read the endpoint event to obtain sessionId. After a victim running SSE mode visits that page, the attacker can use the disclosed sessionId against /message to send unauthorized MCP tool calls. Depending on the configured tools, those calls can read or write local files, execute commands or perform other actions. Binding only to loopback does not prevent this browser-mediated attack. This issue is fixed in version 0.5.0.
- Record
EUVD-2026-114460- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L - Updated
- 2026-11-06
NVD
9.6
MoLing is a computer-use and browser-use based MCP server. Prior to 0.5.0, when MoLing runs in SSE mode using -l, its /sse and /message HTTP endpoints do not authenticate requests and the mcp-go dependency sets Access-Control-Allow-Origin: *. A malicious web page can open a cross-origin EventSource to /sse, including a loopback listener, and read the endpoint event to obtain sessionId. After a victim running SSE mode visits that page, the attacker can use the disclosed sessionId against /message to send unauthorized MCP tool calls. Depending on the configured tools, those calls can read or write local files, execute commands or perform other actions. Binding only to loopback does not prevent this browser-mediated attack. This issue is fixed in version 0.5.0.
- Record
CVE-2026-62863- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L - Weakness
- CWE-306, CWE-942
- Updated
- 2026-11-06
OSV
9.6
MoLing: unauthenticated SSE and wildcard CORS expose tool sessions
MoLing is a computer-use and browser-use based MCP server. Prior to 0.5.0, when MoLing runs in SSE mode using -l, its /sse and /message HTTP endpoints do not authenticate requests and the mcp-go dependency sets Access-Control-Allow-Origin: *. A malicious web page can open a cross-origin EventSource to /sse, including a loopback listener, and read the endpoint event to obtain sessionId. After a victim running SSE mode visits that page, the attacker can use the disclosed sessionId against /message to send unauthorized MCP tool calls. Depending on the configured tools, those calls can read or write local files, execute commands or perform other actions. Binding only to loopback does not prevent this browser-mediated attack. This issue is fixed in version 0.5.0.
- Record
CVE-2026-62863- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L - Weakness
- CWE-306, CWE-942
- Updated
- 2026-11-07
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | NVD, OSV | |
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-62863 is a critical vulnerability (CVSS 9.6) in Gojue Moling, published October 30, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.31%, the 24th percentile. No source names a fixed version.
References
github.com/gojue/moling/security/advisories/GHSA-qpgh-hp5g-4vwp
github.com/gojue/moling/pull/48
github.com/gojue/moling/commit/ae07f704cbc88d4419fc0fbaec278090fcd0502d
github.com/gojue/moling/releases/tag/v0.5.0
github.com/CVEProject/cvelistV5/tree/main/cves/2026/62xxx/CVE-2026-62863.json
nvd.nist.gov/vuln/detail/CVE-2026-62863