CVE-2026-25687 ZCC race condition in ZPA tunnel handler
A race condition in the Zscaler Client Connector tunnel handler allows attackers to cause a crash or potentially execute arbitrary code.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-25687?
CVE-2026-25687 is a high-severity vulnerability in Zscaler Client Connector, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A race condition in the ZPA tunnel handler of affected versions of Zscaler Client Connector (ZCC) allows a heap corruption, resulting in a denial of service (client crash) and potentially arbitrary code execution in the context of the ZCC process.
Weakness: CWE-366
Which versions are affected by CVE-2026-25687?
How do I fix CVE-2026-25687?
No fix has been published for CVE-2026-25687 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-25687 being exploited?
There is no known exploitation of CVE-2026-25687 in the wild and no public exploit code.
Sources
Also known as GHSA-4wwc-hgc4-j27v.