Vulnerability · Published Sep 28, 2026 · Assigned by Zscaler
CVE-2026-59563HMAC Confirmation Token Unbinding in zscaler-mcp-server
Medium 4.6
In plain English
A medium-severity security flaw in zscaler-mcp-server from Zscaler. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities).
Severity (CVSS 3.1)4.6Medium
Exploit odds (30 days)0.1%top 97.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Zscaler MCP Server versions 0.7.0 and 0.7.1 has an issue where HMAC confirmation tokens were not bound to the target resource identifier, allowing an MCP client or agent to replay a token generated for one resource to affect another resource of the same type. This issue is fixed in version 0.7.2.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Zscaler | zscaler-mcp-server | 0.7.0 – before 0.7.2 |
Weakness: CWE-305 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:L