Is there a public exploit for CVE-2026-87043?

No public exploit for CVE-2026-87043 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-87043?

CVE-2026-87043 scores CVSS 4.8 (v3.1), rated medium.

What does CVE-2026-87043 affect?

CVE-2026-87043 affects zephyrproject Zephyr.

4.8 Medium

The entropy-device random number generator in subsys/random/randomentropydevice.c returned early with -ENODEV from randget() as soon as…

CVE-2026-87043

The entropy-device random number generator in subsys/random/randomentropydevice.c returned early with -ENODEV from randget() as soon as deviceisready() failed, before reaching the non-cryptographic system-timer fallback further down the same function. Because zimplsysrandget() returns void and discards that error — and the public sysrandget() syscall is itself declared void, so it cannot report failure — the caller's output buffer was left untouched and its previous contents were handed back as random data. The thin wrappers make this a plain uninitialized read: sysrand32get() declares uint32t ret;, calls sysrandget(&ret, sizeof(ret)) and returns ret. The "not ready" state is a normal runtime condition rather than a fault. Entropy drivers initialise at PREKERNEL1 with CONFIGENTROPYINITPRIORITY (default 50), so any earlier initialiser — kernel objects run at priority 30 — observes an unready device; the sibling generator subsys/random/randomxoshiro128.c and zearlyrandget() in kernel/init.c both already carried an explicit timer fallback for exactly this case. The state is also permanent for the boot when an entropy driver's init hook fails, which several in-tree drivers can do on…

Assessment

CVSS: 4.8 (v3.1)
Severity: Medium
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 4 November 2026
Last updated: 4 November 2026
Affected: zephyrproject · Zephyr
Assigner: zephyr

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

At the source

EUVD (ENISA)

References

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