CVE-2026-2336: Weak webstax_auth Cookie Authentication Allows Privilege Escalation

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-16 · updated 2026-10-26
Weakness: CWE-331

Description

A privilege escalation vulnerability in Microchip IStaX allows an authenticated low-privileged user to recover a shared per-device cookie secret from their own webstax_auth session cookie and forge a new cookie with administrative privileges.This issue affects IStaX before 2026.03.

Affected products

Microchip IStaX: before 2026.03 — fixed in 2026.03

How to fix

Upgrade to a fixed version: Microchip IStaX 2026.03. Check the vendor advisory for mitigations.

References

https://www.microchip.com/en-us/solutions/technologies/embedded-security/how-to-report-potential-product-security-vulnerabilities/istax-privilege-escalation-via-weak-cookie-authentication

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