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.

Published: 2019-09-02 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-15847 is rated Moderate Risk (63/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.21%). EPSS rose +2.71% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2019-15847

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.49% 3.21% +2.71%
2 2026-04-12 0.74% 0.49% -0.25%
3 2026-03-28 — 0.74% —

Full EPSS history (18 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-15847

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2019-15847

OS Trackers for CVE-2019-15847

vendor priority summary link
alpine high CVE-2019-15847: 1 source package rows (gcc); 1 state rows across 1 repos (3.11-main); fixed 1, open 0. https://security.alpinelinux.org/vuln/CVE-2019-15847
debian low CVE-2019-15847 low priority: Debian including 1 source packages (gcc-9), 1 status rows across 1 suites (bullseye): resolved 1. https://security-tracker.debian.org/tracker/CVE-2019-15847
gentoo normal CVE-2019-15847: 1 GLSA(s) (202409-22), 1 atom(s) (sys-devel/gcc); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2019-15847
redhat medium — https://access.redhat.com/security/cve/CVE-2019-15847
suse medium CVE-2019-15847 severity moderate: SUSE including 1623 source package names (0.0.17-1.1:libgcc_s1-9.2.1+r275327-1.3.7, 0.0.17-1.1:libstdc++6-9.2.1+r275327-1.3.7, …), 7249 product×package rows across 706 product lines (Container bci/bci-base-fips, Container bci/bci-init, … (706 product lines)): Fixed 5017, Known Not Affected 2001, Known Affected 231. https://www.suse.com/security/cve/CVE-2019-15847/
ubuntu negligible CVE-2019-15847 negligible priority: Ubuntu including 45 source packages (gcc-10, gcc-3.3, …), 808 status rows across 18 suites (bionic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 518, not-affected 195, ignored 48, needs-triage 39, released 8. https://ubuntu.com/security/CVE-2019-15847

Affected software / configurations for CVE-2019-15847

Vendor Product Version Raw CPE
gnu gcc < 7.5.0 cpe:2.3:a:gnu:gcc:*:*:*:*:*:*:*:*
gnu gcc >= 8.0, < 8.4.0 cpe:2.3:a:gnu:gcc:*:*:*:*:*:*:*:*
gnu gcc >= 9.0, < 9.3.0 cpe:2.3:a:gnu:gcc:*:*:*:*:*:*:*:*
gnu gcc >= 10.0, < 10.1.0 cpe:2.3:a:gnu:gcc:*:*:*:*:*:*:*:*
opensuse leap 15.0 cpe:2.3:o:opensuse:leap:15.0:*:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*

References for CVE-2019-15847

cvelogic Threat Intelligence