CVE-2026-107612: World-accessible IPC shared memory with predictable name in TightVNC Server

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-08 · updated 2026-10-08
Weakness: CWE-338

Description

Incorrect permission assignment in GlavSoft TightVNC Server for Windows before 2.8.88 allows a local authenticated user to read or overwrite the inter-process communication handles used between the TightVNC service and its desktop server process. The named shared memory segment in the Global\ namespace that carries the pipe HANDLE values is created with a NULL DACL, and its name is derived from a time-seeded srand(time(0)) value that is predictable to one-second granularity. A low-privileged local process can open the mapping and tamper with the IPC channel of a service running as SYSTEM, potentially leading to disclosure of session data, privilege escalation, or denial of service.

Affected products

GlavSoft TightVNC: before 2.8.88 — fixed in 2.8.88

How to fix

Upgrade to a fixed version: GlavSoft TightVNC 2.8.88. Check the vendor advisory for mitigations.

References

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