CVE-2026-81099
Timescale tiger-slack DNS Rebinding via Disabled Host Header Allow-List
- State
- Published
- Severity
- 7.6 High
- Published
- Aug 27, 2026
- Updated
- Aug 29, 2026
- Reserved
- Aug 26, 2026
Description
tiger-slack started its MCP HTTP transport without enabling the host allow-list the underlying SDK provides. mcp/src/httpServer.ts called the shared httpServerFactory helper and never set the DNS-rebinding-protection option, so the transport accepted a request whatever host it named, and a page in a browser could point a name it controlled at the address the server was bound to and drive the locally reachable Slack MCP server through the visitor's browser. The fix passes the option explicitly alongside a dependency update; the update alone would not have closed it. The repository publishes no release that brackets the fix, so the affected boundary is the commit preceding it.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.6 High | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 6.8 Medium | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N | VulnCheck |
Weaknesses
- CWE-346 Origin Validation Error
Affected Products
| Product | Versions |
|---|---|
tiger-slacktimescale |
|
References
- https://github.com/timescale/tiger-slackproduct
- https://github.com/timescale/tiger-slack/pull/146issue-trackingpatch
- VulnCheck Advisory: Timescale tiger-slack DNS Rebinding via Disabled Host Header Allow-Listthird-party-advisory
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