CVE-2026-43809
Out-of-bounds read in macOS may crash apps or the system (denial of service).
Is CVE-2026-43809 being exploited?
Not confirmed. CVE-2026-43809 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 0.62% probability of exploitation in the next 30 days.
How severe is CVE-2026-43809?
CVE-2026-43809 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-2026-43809?
Yes. A fix has been recorded for CVE-2026-43809. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-43809 affect?
CVE-2026-43809 affects macOS Sequoia <15.7.8, macOS Sonoma <14.8.8, macOS Tahoe <26.6. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-43809?
Update Macs to Sequoia 15.7.8, Sonoma 14.8.8 or Tahoe 26.6 immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
A malicious or buggy app can trigger an out‑of‑bounds read causing unexpected app or system termination (local or remote DoS).
Immediate action required
- affected< 18.7.10
- affected< 14.8.8
- affected< 15.7.8
- affected< 26.6
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.