CVE-2019-15847: GNU Gcc

High severity, CVSS 7.5. EPSS: 3.2% chance of exploitation in the next 30 days.

The POWER9 backend in GNU Compiler Collection (GCC) before version 10 could optimize multiple calls of the __builtin_darn intrinsic into a single call, thus reducing the entropy of the random number generator. This occurred because a volatile operation was not specified. For example, within a single execution of a program, the output of every __builtin_darn() call may be the same.

Affected products

• GNU Gcc: before 7.5.0 (fixed in 7.5.0); from 8.0, before 8.4.0 (fixed in 8.4.0); from 9.0, before 9.3.0 (fixed in 9.3.0); from 10.0, before 10.1.0 (fixed in 10.1.0)
• Opensuse Leap: version 15.0 only; version 15.1 only

Published 2019-09-02. Last modified 2026-06-17.