CVE-2019-15847

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.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

3.2% chance of exploitation in the next 30 days; higher than 87% of CVEs (scores of 2026-10-25)

CWE

CWE-331

Published

2019-09-02

Modified

2026-10-14

Record from

the NVD, synced 2026-10-19

Affected

• gnu:gcc
• opensuse:leap

References

• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00056.html
• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00057.html
• http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00058.html
• https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91481
• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00056.html

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