What is CVE-2026-84559?

CVE-2026-84559 is A permissions issue was addressed with improved validation. The supplied enrichment data classifies it as Unclassified mapped to CWE-693 CWE-693.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-84559. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-84559 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

A public PoC is not confirmed from current sources for CVE-2026-84559. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with Not reported where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-84559 using CVSS 5.5, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

medium

CVE-2026-84559

CVE-2026-84559 — A permissions issue was addressed with improved validation

A permissions issue was addressed with improved validation. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. A malicious application may be able to access restricted files.

Published Sep 14, 2026Updated Sep 14, 2026Sources: NVD, Apple (CNA), GitHub, GitHub Security Advisory, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

ahead of 0% of scored CVEs

Affects

Apple

3 products listed

CVSS base

5.5

medium

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Upgrade macOS to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
Apple	macOS	0 to < 15.8	Vulnerable
Apple	macOS	0 to < 26.7	Vulnerable
Apple	macOS	0 to < 27	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

None

Confidentiality

High

Integrity

None

Scope

Unchanged

Attack Complexity

Low

Attack Vector

Local

Privileges Req

Low

User Interaction

None

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
5.5	CVSS 3.1	medium	—	—	CVE Program

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

Weakness & attack patterns

CWE-693

Inferred from the weakness class — not observed against this CVE.

T1574.010Hijack Execution Flow: ServicesFile Permissions Weakness
T1083File and Directory Discovery
T1574.005Hijack Execution Flow: Executable Installer File Permissions Weakness

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 5.5 (AV:L)
Sep 14, 2026 · NVD
Initial · CVE published
Sep 14, 2026 · NVD
Added · GHSA-f4vr-w4mm-6rgv published (unknown)
Sep 14, 2026 · GitHub Security Advisory
CVE published by MITRE.
Sep 14, 2026 · SOCRadar CTI

References

5 on the record

support.apple.com/en-us/149035
Vendor Advisory
support.apple.com/en-us/149042
Vendor Advisory
support.apple.com/en-us/149043
Vendor Advisory
nvd.nist.gov/vuln/detail/CVE-2026-84559
NVD
github.com/advisories/GHSA-f4vr-w4mm-6rgv
Exploit, Third Party Advisory

Coverage

1 story from the feeds we poll

The Apple Security Update Review for September 2026
Zero Day Initiative · Sep 16, 2026

Elsewhere on this site

Appleevery CVE for this vendor
Unclassifiedsame class
CWE-693other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2026-84559 is A permissions issue was addressed with improved validation, a medium vulnerability affecting macOS from Apple. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-84559. Public exploit evidence is: A public PoC is not confirmed from current sources for CVE-2026-84559. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 5.5 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.