Medium severity · published Sep 28, 2026
CVE-2026-59563
HMAC Confirmation Token Unbinding in zscaler-mcp-server
4.6
CVSS
0.1%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:L
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
None
Integrity
Low
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ZS
zscaler-mcp-server · Zscaler
0.7.0 before 0.7.2 · source: vendor