CVE-2026-81099

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

MEDIUM
6.8
CVSS Score
Published: August 27, 2026 at 02:50 PM UTC
Updated: September 23, 2026 at 05:30 PM UTC
1 product affected across 1 vendorTiger Slack

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Severity
MEDIUM6.8
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 23faf7ee7e7f73e5ea4f67e627c1aca94bba1f09
Vendor states this is fixed in 23faf7ee7e7f73e5ea4f67e627c1aca94bba1f09 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.8MEDIUMVulnCheck
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-346

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