Out-of-bounds Read in Apple macOS
CVE-2026-84543
An out-of-bounds access issue was addressed with improved bounds checking. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. Connecting to a malicious SMB server may cause unexpected system termination or corrupt kernel memory.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (37.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- support.apple.com/en-us/149035 (Release Notes, Vendor Advisory)
- support.apple.com/en-us/149042 (Release Notes, Vendor Advisory)
- support.apple.com/en-us/149043 (Release Notes, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-84543?
- CVE-2026-84543 is a high-severity vulnerability in Apple macOS, classified under Out-of-bounds Read. CVSS score: 7.5/10. Published 2026-09-14.
- How severe is CVE-2026-84543?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2026-84543 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.