Kernel-level buffer overflow in widely used Apple macOS (CVSS 9.8). Kernel corruption or crashes can disrupt enterprise endpoints and may lead to privilege escalation; newsworthy and broad impact.
CVE-2026-84520
Local kernel buffer overflow in macOS Golden Gate may crash or corrupt kernel memory.
Is CVE-2026-84520 being exploited?
Not confirmed. CVE-2026-84520 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.45% probability of exploitation in the next 30 days.
How severe is CVE-2026-84520?
CVE-2026-84520 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-84520?
Yes. A fix has been recorded for CVE-2026-84520. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-84520 affect?
CVE-2026-84520 affects Apple macOS (pre-Golden Gate 27). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-84520?
Install macOS Golden Gate 27 update immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Local attacker can corrupt kernel memory or trigger system crashes, causing denial-of-service and possible privilege escalation.
Immediate action required
- affected< 27
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
public exploits
Unvetted proof-of-concept code on GitHub: 1 GitHub proof of concept
- csrXamfi/CVE-2026-84520 · 1 ★
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
cisa ssvc
- exploitation
- none
- automatable
- yes
- technical impact
- total
Assessed by CISA 16 Sept 2026 (SSVC 2.0.3).
timeline
- 14 Sept 2026Published
- 16 Sept 2026CISA SSVC assessment: exploitation none · 2 days later
- 17 Sept 2026Analysed by vulneraibility.com · 1 day later
- 10 Oct 2026First proof-of-concept repository on GitHub (unvetted) · 22 days later
- 26 Oct 2026CVE record last updated · 17 days later
- Linksupport.apple.com /en-us/149035
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.