Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
🛡️
Not in CISA KEV
HIGH severity

CVE-2026-43815 — MACOS

HIGH

CVE-2026-43815 is a high-severity (CVSS 8.8) Out-of-bounds Write vulnerability in apple macos. A fix is available — see the affected versions and patch details below.

A buffer overflow was addressed with improved bounds checking. This issue is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6. Connecting to a malicious afpfs server…

Published
Updated
Affected
1 product
Patched
See advisory
Exploits
None indexed
Exploitation data as of Oct 13, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • A successful exploit gives an attacker total control of the affected component, not partial access.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-43815.

EPSS Exploitation Probability

via FIRST.org ↗
0.5%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs40th percentile — riskier than 40% of all scored CVEsHighest risk
0.00%0.33%0.65%0.98%0.5%0.5%Oct 26Oct 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-43815 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 386,684 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Description

A buffer overflow was addressed with improved bounds checking. This issue is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6. Connecting to a malicious afpfs server may lead to kernel memory corruption.

Affected Products

1 product · 3 configurations
OS
macosapple
≥ 26.0 && < 26.6
range

Detection & mitigation playbook

Vendor / appliance

  1. Detect

    Inventory every apple macos deployment and check each version against the affected-products list above.

  2. Fix

    Apply the apple macos security patch or hotfix for CVE-2026-43815 on the affected version, following the vendor advisory for your exact build.

  3. Workarounds

    Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Frequently Asked Questions

A buffer overflow was addressed with improved bounds checking. This issue is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6. Connecting to a malicious afpfs server may lead to kernel memory corruption.
O3 Security · Runtime Protection

Is CVE-2026-43815 being exploited in your environment?

Detect and block the exploit chain at execution, on systems you cannot patch yet.

Protect my workloads How runtime protection works
CVE-2026-43815: MACOS Memory Corruption (High 8.8)