Vulnerability · Published Aug 27, 2026 · Assigned by VulnCheck

CVE-2026-81099Timescale tiger-slack DNS Rebinding via Disabled Host Header Allow-List

Medium 6.8

In plain English

A medium-severity security flaw in tiger-slack from timescale. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities).

Severity (CVSS 3.1)6.8Medium

Exploit odds (30 days)0.2%top 87.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
timescale	tiger-slack	0 – before 23faf7ee7e7f73e5ea4f67e627c1aca94bba1f09

Weakness: CWE-346 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

References

https://github.com/timescale/tiger-slack product
https://github.com/timescale/tiger-slack/pull/146 issue-tracking, patch
VulnCheck Advisory: Timescale tiger-slack DNS Rebinding via Disabled Host Header Allow-List third-party-advisory