CVE-2026-84589

Executive Summary

CVE-2026-84589 is a local permissions flaw in Apple macOS that was resolved through "additional restrictions" added to a Privacy preference modification path. An attacker operating a local application context (low-privilege, no user interaction) may be able to modify Privacy preferences that should be protected by system-enforced access controls. The vulnerability carries a CVSS v3.1 base score of 5.5 (Medium), with a documented Integrity-only impact and no confidentiality or availability impact, and Apple states the issue is fixed in macOS Golden Gate 27.

Technical Analysis

The NVD description states: "A permissions issue was addressed with additional restrictions. This issue is fixed in macOS Golden Gate 27. An app may be able to modify Privacy preferences." The assigned CWE is CWE-863 (Incorrect Authorization), which categorizes this as a failure to properly enforce authorization checks on a protected resource or operation rather than a memory-safety defect or injection flaw.

The CVSS vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N maps to the following meaning for defenders:

• AV:L (Local): The attack is not remotely reachable over a network; it requires the attacker to already have code executing on the target macOS host, or local access through another vector.
• AC:L (Low): No special conditions beyond normal operation are required to trigger the flaw once the attacker has local access.
• PR:L (Low): The attacker requires low privileges — consistent with the description that "an app" can trigger the behavior.
• UI:N (None): No user interaction, such as clicking a dialog or approving a prompt, is required.
• S:U (Unchanged): A successful exploit does not change the security scope; its impact remains confined to the same authority level as the vulnerable component.
• C:N / I:H / A:N: There is no direct loss of confidentiality or availability, but there is a High impact to integrity.

Applying CWE-863 to the macOS context: Privacy preferences are the user- and system-controlled settings that govern which applications may access sensitive subsystems (for example, categories historically governed by macOS privacy controls such as camera, microphone, location, contacts, and similar protected resources). The defect is that an application with low privileges was able to reach and modify these preference records via a path that lacked the correct authorization enforcement. The remediation pattern ("addressed with additional restrictions") indicates Apple did not rewrite the subsystem but instead tightened the authorization gate so that the low-privileged application context no longer satisfies the required restriction.

Because the NVD entry is sparse, no specific function names, class names, URL schemes, API parameters, XPC endpoints, file paths, or preference-domain identifiers are provided. Any claim about a specific entitlement, TCC database table, or daemon name would be speculative and is therefore omitted here. The essential technical fact remains: the flaw is a broken authorization constraint on a local, privileged preference-modification operation, yielding an integrity-only violation.

Exploitation Scenarios

No public proof-of-concept, exploit code, or Nuclei template exists for this CVE as of the source data. The attack chain below is described strictly at the vulnerability-class level (incorrect authorization on a local preference-modification operation) and does not assert any unconfirmed implementation detail.

1. Reconnaissance / target identification. The attacker first needs code execution on a macOS host running a version prior to Golden Gate 27. This is typically achieved through a separate initial-access vector — a malicious or trojanized application, a supply-chain-compromised app, a malicious installer, or another local foothold. The attacker enumerates the macOS build/version to confirm the target predates the fixed release.

2. Triggering the flaw class. The attacker's low-privileged application performs a request to modify a Privacy preference setting. Under CWE-863, the vulnerable component fails to enforce the authorization restriction that should gate modification of that preference. Because AC:L and UI:N apply, no special conditions and no user approval prompt are needed for the request to be honored on a vulnerable host.

3. Execution method at the vulnerability-class level. The malicious local application makes the preference-modification request directly. The vulnerability is that the authorization check is insufficient — the operation succeeds where it should have been rejected for a low-privileged caller. No injected payload technique, crafted argument, or named API call can be asserted from the available description.

4. Post-exploitation impact. Successful modification of Privacy preferences allows the attacker to weaken or alter privacy-related permissions, which can serve as a precursor to broader surveillance or data-collection capability. Consistent with the CVSS vector (I:H, C:N, A:N), the immediate measurable effect is integrity loss — the tampered configuration no longer reflects the user's intended or the system's enforced state — rather than direct data exfiltration or disruption.

Note that a meaningful exploitation precondition is the pre-existing local foothold; this CVE is not network-reachable and cannot be used as a standalone initial-access method.

Impact Assessment

The blast radius of this vulnerability is bounded by its AV:L rating: only hosts where the attacker already has local low-privileged code execution are at risk. CVSS subscores:

• Confidentiality: None (C:N) — the flaw itself does not directly disclose protected data.
• Integrity: High (I:H) — the attacker can alter Privacy preference state that should be immutable from a low-privileged context.
• Availability: None (A:N) — no denial-of-service effect is described. The base score is 5.5 (Medium). The EPSS score is 0.00173, placing the CVE at roughly the 7.0th percentile of exploited CVEs — i.e., low near-term exploitation likelihood by current modeling. CISA KEV status is NO, meaning there is no confirmed in-the-wild exploitation tracked by CISA.

From a business perspective, the primary risk is post-compromise privilege/integrity manipulation on managed macOS fleets. Because Privacy preferences govern access to sensitive subsystems, an attacker who can modify them may enable additional data-collection capability that bypasses expected user consent controls. For enterprises with macOS endpoints (developer workstations, executive laptops, creative/production fleets), the impact is a weakened local privacy/consent posture that can conceal or enable follow-on collection activity. The unchanged-scope rating means the flaw does not by itself grant broader system authority, limiting the practical blast radius to the integrity of privacy configuration.

Detection Guidance

The rules below are detection hypotheses for a local authorization-integrity defect. Because no concrete API, path, or parameter is published, the rules target anomalous modification of macOS privacy/TCC configuration and associated process behavior rather than a confirmed signature.

Sigma Rule

title: Suspicious Modification of macOS Privacy Preference Store
id: 7c1e9a44-8b2d-4f13-9a67-0f5d2c6b1e84
status: experimental
description: Detects non-system or low-privileged processes writing to macOS privacy/TCC configuration stores, consistent with CVE-2026-84589 (CWE-863).
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-84589
author: valtersit.com
date: 2026/01/01
logsource:
  product: macos
  category: file_event
detection:
  selection_path:
    TargetFilename|contains:
      - '/Library/Application Support/com.apple.TCC/'
      - 'TCC.db'
      - '/Library/Preferences/com.apple.'
  selection_priv:
    TargetFilename|contains: 'Privacy'
  filter_system:
    Image|startswith:
      - '/System/'
      - '/usr/libexec/'
      - '/usr/sbin/'
  condition: (selection_path or selection_priv) and not filter_system
falsepositives:
  - Legitimate system daemons and MDM agents updating preferences
  - Apple-signed privacy configuration utilities
level: medium
tags:
  - attack.privilege_escalation
  - attack.t1068

YARA Rule

rule CVE_2026_84589_macOS_Privacy_Pref_Abuse
{
    meta:
        description = "Heuristic detection of macOS binaries referencing privacy preference modification paths associated with CVE-2026-84589"
        author = "valtersit.com"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-84589"
        date = "2026-01-01"
        cve = "CVE-2026-84589"

    strings:
        $tcc1 = "com.apple.TCC" ascii wide
        $tcc2 = "TCC.db" ascii wide
        $priv1 = "Privacy" ascii wide
        $pref1 = "com.apple.security.privacy" ascii wide
        $pref2 = "kTCCService" ascii wide

    condition:
        uint32(0) == 0xfeedfacf and   // Mach-O 64-bit
        filesize < 50MB and
        (
            ($priv1 and $pref2) or
            ($tcc1 and $priv1) or
            ($tcc2 and $priv1) or
            ($pref1 and ($tcc1 or $tcc2))
        )
}

Suricata IDS Rule

alert tcp $HOME_NET any -> $HOME_NET any (msg:"CVE-2026-84589 Possible macOS Privacy Preference Modification Attempt (local, informational)"; flow:to_server,established; content:"com.apple.TCC"; nocase; content:"Privacy"; nocase; threshold: type limit, track by_src, count 1, seconds 60; classtype:attempted-admin; sid:9004589; rev:1; metadata:cve CVE-2026-84589, cwe CWE-863;)

Elastic Detection

file where host.os.type == "macos" and
  event.action in ("creation", "modification", "rename") and
  (
    file.path :
      ("/Library/Application Support/com.apple.TCC/*",
       "*/TCC.db*",
       "*/com.apple.TCC/*") or
    file.name : "TCC.db"
  ) and
  not process.executable :
    ("/System/*",
     "/usr/libexec/*",
     "/usr/sbin/*",
     "/usr/bin/tccutil")

Splunk SPL Query

index=macos sourcetype=osquery_results OR sourcetype=macos_unified_logs
(process_name=* OR path=*)
(path="*com.apple.TCC*" OR path="*TCC.db*" OR message="*Privacy*" OR message="*TCC*")
| where NOT match(process_path, "^/System/") AND NOT match(process_path, "^/usr/libexec/")
| stats count min(_time) as first_seen max(_time) as last_seen values(process_path) as processes values(process_name) as names by host
| convert ctime(first_seen) ctime(last_seen)
| sort - count

Wazuh OSSEC Rule

<group name="macos,cve-2026-84589,">
  <rule id="100589" level="10">
    <decoded_as>json</decoded_as>
    <field name="path">\.TCC\.db|com\.apple\.TCC|Privacy</field>
    <field name="process_name" negate="yes">tccutil|mdmclient|cfprefsd</field>
    <description>CVE-2026-84589: Suspicious modification of macOS privacy preference store by non-system process</description>
    <mitre>
      <id>T1068</id>
    </mitre>
    <group>privilege_escalation,integrity,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 2/4 (CLAIMED — single source claims patch (not independently confirmed)). Vendor fix, workarounds, and affected version ranges were not supplied in the source data, so the guidance below is accordingly limited.

1. Immediate mitigations

   • Until the patch is validated for your fleet, constrain local code execution: enforce application allowlisting and blocking of unsigned/ad-hoc-signed binaries on macOS endpoints.
   • Monitor and alert on anomalous writes to macOS privacy/consent configuration by non-system processes (see Detection Guidance).
   • Apply least-privilege principles for local user accounts; because PR:L applies, reducing the number of accounts able to run arbitrary applications reduces exposure.
   • Treat the presence of any unexplained application with local execution capability as a potential trigger for this flaw class.

2. Patch/upgrade steps

   • Upgrade affected macOS hosts to macOS Golden Gate 27, which Apple specifies as the fixed release per the NVD description.
   • Because patch confidence is only 2/4 and the patch is claimed by a single source (NVD) and not independently confirmed, verify build identifiers and Apple advisory details before declaring endpoints remediated. Confirm the fix covers your specific OS branch.
   • Validate the update on a representative pilot group before broad deployment.

3. Long-term hardening

   • Establish continuous OS/Build inventory so unsupported or pre-fix macOS versions are identifiable and reportable.
   • Deploy endpoint detection tuned to privacy/consent store tampering and correlate with process lineage.
   • Maintain an MDM baseline that detects drift in privacy/consent configuration, since this CVE's impact is integrity of that state.
   • Track this CVE in vulnerability management; note that low EPSS (~0.00173) and non-KEV status mean it is lower priority than remotely exploitable, KEV-listed issues, but it remains relevant for post-compromise integrity protection.

References

• NVD — CVE-2026-84589: https://nvd.nist.gov/vuln/detail/CVE-2026-84589
• Apple Security Releases (macOS Golden Gate 27 coverage): https://support.apple.com/en-us/HT201222
• MITRE CWE-863 — Incorrect Authorization: https://cwe.mitre.org/data/definitions/863.html
• MITRE ATT&CK T1068 — Exploitation for Privilege Escalation: https://attack.mitre.org/techniques/T1068/
• FIRST EPSS: https://www.first.org/epss/ (CVE-2026-84589 score 0.00173)

Threat actor campaigns / exploit-in-the-wild evidence: None identified. CISA KEV status is NO, no public PoC or exploit code is available, and no Nuclei template exists. Exploitation activity has not been confirmed in the source data.