CVE-2026-84624

Executive Summary

CVE-2026-84624 is a path validation flaw (CWE-22) in Apple operating systems that permits a sandboxed application to escape intended file-access restrictions and read files it should not be able to reach. The issue is rated CVSS 3.1 base score 5.5 (Medium), with high confidentiality impact but no integrity or availability impact, and requires local access plus a degree of user interaction. All users of unpatched iOS, iPadOS, macOS, and visionOS builds listed by the CNA are potentially affected, though the practical blast radius is limited by the need to convince a user to install or launch a malicious sandboxed app.

Technical Analysis

Per the NVD description, the vulnerability is "a permissions issue" that "was addressed with improved path validation," and the stated consequence is that "a sandboxed app may be able to access restricted files." The associated weakness is CWE-22 (Improper Limitation of a Pathname to a Restricted Directory, i.e., path traversal). Taken together, these two facts define the mechanism at the level of vulnerability class: the operating system's sandbox enforces filesystem access boundaries partly through pathname validation, and that validation was insufficient — an application running inside the sandbox could construct or supply a path (for example, via sequences that resolve outside the intended directory) that the validation logic failed to reject, causing the system to resolve the path to a location outside the sandbox's permitted scope.

No further implementation specifics are available. The CNA title is empty and the NVD description does not name the affected subsystem, the validation routine, or the exact traversal form. It is therefore not possible, from the provided data, to identify the concrete API, path, or parsing behavior that was deficient. What can be stated with confidence is the class of defect and its security consequence: a sandbox containment failure rooted in pathname handling, resolved by tightening path validation. The absence of public PoC, exploit code, or Nuclei template (all confirmed absent in the supplied data) means no weaponized or reproducible detail is public at the time of writing.

The CVSS vector CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N is consistent with this class: local attack vector (the app executes on the target device), low attack complexity, no privileges required, user interaction required (the user must run or install the sandboxed app), unchanged scope, and a high confidentiality-only impact — i.e., the attacker reads restricted files but does not modify them or affect availability.

Exploitation Scenarios

No public PoC is available; the following attack chain is inferred from the vulnerability class (CWE-22 path traversal within a sandbox) and the CVSS vector, and deliberately avoids naming any specific function, path, or parameter not present in the source data.

1. Reconnaissance / target identification. There is no network-facing reconnaissance surface described for this flaw. The attacker's "reconnaissance" is limited to selecting a victim who will install and launch a sandboxed application from a distribution channel the attacker controls (or a trojanized legitimate app), given AV:L and UI:R. The affected population is any unpatched build of the Apple OS versions listed in the metadata.

2. Triggering the flaw class. The malicious app, running inside its sandbox, supplies a crafted pathname to a file-access operation. Because path validation is inadequate, the path resolves to a location outside the sandbox's permitted directory — the classic traversal condition under CWE-22. The exact traversal construction is unknown from the available data; at class level it is a pathname that the validation routine fails to normalize or reject before the OS resolves it.

3. "Execution" / data access method. This is not a code-execution vulnerability. The payload is the crafted path plus the file-read operation; the outcome is the app receiving file contents it is not entitled to read. Exploitation succeeds when the sandbox returns data from the out-of-scope location instead of denying access.

4. Post-exploitation impact. The app reads restricted files (C:H), with no integrity or availability effect (I:N/A:N). The value of the exfiltration depends entirely on which files the sandbox was meant to protect; the description does not enumerate them. Data would then typically be transmitted off-device through the app's own network capability. There is no evidence in the provided data of chaining, privilege escalation beyond the sandbox boundary, or in-the-wild exploitation.

Impact Assessment

Business impact centers on unauthorized disclosure of device-restricted data. The CVSS subscores make this explicit: Confidentiality High, Integrity None, Availability None, with Scope Unchanged. Attack Vector is Local and User Interaction is Required, which constrains exploitation to scenarios where a user installs or launches attacker-influenced sandboxed software. Privileges Required is None and Attack Complexity is Low, meaning once the malicious app is running, successful exploitation is not expected to require special conditions. The blast radius is per-device and per-user rather than server-side or cross-tenant, but in managed enterprise fleets of Macs, iPhones, iPads, and Vision Pro devices, a single successful malicious app could read restricted files on each host where it is installed. CVSS base 5.5 (Medium) reflects the confidentiality-only, interaction-gated profile. EPSS is 0.00168 (6.5th percentile), indicating very low near-term exploitation likelihood; the CVE is not in CISA KEV and no exploit code or PoC is known.

Detection Guidance

Detection for a local sandbox-escape file-access flaw is inherently host-centric: there is no distinctive network signature tied to the CVE itself, so the rules below target anomalous sandboxed-process file access and process/file telemetry rather than a wire-visible exploit. Because specific paths and APIs are unknown, detections are written generically and should be tuned against the affected OS versions.

Sigma Rule

title: Sandboxed Application Access to Restricted File Paths (CVE-2026-84624 class)
id: 8f2a1c44-7b3e-4d21-9c6a-000000084624
status: experimental
description: Detects a sandboxed process opening files outside its expected container, consistent with a path-validation/sandbox-escape flaw (CWE-22) as described for CVE-2026-84624.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-84624
author: valtersit.com
date: 2026/01/01
logsource:
  category: file_event
  product: macos
detection:
  selection_sandbox:
    Image|contains:
      - '/Library/Containers/'
      - '/var/folders/'
  selection_restricted:
    TargetFilename|startswith:
      - '/private/var/'
      - '/Library/'
      - '/Users/Shared/'
  selection_traversal:
    TargetFilename|contains:
      - '../'
      - '..%2f'
  condition: selection_sandbox and selection_restricted
  # optional higher-fidelity variant: selection_sandbox and selection_restricted and selection_traversal
falsepositives:
  - Legitimate sandboxed apps with broadly scoped file entitlements
level: medium
tags:
  - attack.privilege_escalation
  - attack.t1068
  - cve.2026.84624

YARA Rule

rule CVE_2026_84624_Sandbox_PathTraversal_Strings
{
    meta:
        description = "Hunts for artifacts/strings consistent with path-traversal sandbox escape (CVE-2026-84624, CWE-22). Generic indicators only; no public PoC exists."
        author = "valtersit.com"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-84624"
        date = "2026-01-01"
        severity = "medium"

    strings:
        $trav1 = "../" ascii
        $trav2 = "..\\" ascii
        $trav3 = "..%2f" ascii nocase
        $trav4 = "..%5c" ascii nocase
        $enc1  = "%2e%2e" ascii nocase

    condition:
        uint32(0) == 0xFEEDFACF or uint32(0) == 0xCAFEBABE or uint32(0) == 0x0061736D
        and any of ($trav*) and $enc1
}

Note: this rule flags Mach-O/Java/WebAssembly binaries embedding traversal sequences; it is a heuristic aid, not a definitive CVE detector.

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-84624 Possible Path Traversal Data Exfiltration (Apple sandbox escape class)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:".."; http.uri; content:"%2e"; classtype:attempted-recon; reference:cve,2026-84624; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-84624; sid:9004624; rev:1;)

The flaw itself is local; this rule only covers the plausible follow-on channel (a sandboxed app posting exfiltrated file data or traversal-bearing URIs) and will require tuning.

Elastic Detection

process where event.type == "start" and
  process.executable : ("/private/var/containers/*", "/var/folders/*") and
  process.args : ("*../*", "*..%2f*", "*..\\*")

EQL over process/endpoint telemetry to surface sandboxed processes launched with traversal-bearing arguments.

Splunk SPL Query

index=endpoint (sourcetype=XmlWinEventLog OR sourcetype=macos:unified_log OR sourcetype=osquery)
(process_path="*/Library/Containers/*" OR process_path="*/var/folders/*")
(file_path="*../*" OR file_path="*..%2f*" OR command_line="*../*")
| stats count min(_time) as first_seen max(_time) as last_seen values(file_path) as files by host process_path user
| where count > 0
| sort - count

Wazuh OSSEC Rule

<group name="apple,cve-2026-84624,">
  <rule id="100624" level="7">
    <decoded_as>json</decoded_as>
    <field name="event.category">file</field>
    <field name="process.name">\.+</field>
    <match>\.\./</match>
    <description>CVE-2026-84624: possible sandboxed process accessing restricted path outside its container (path traversal)</description>
    <mitre>
      <id>T1068</id>
    </mitre>
    <group>privilege_escalation,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 2/4 (CLAIMED) — a single source (NVD) states the issue was addressed with improved path validation and is fixed in iOS 26.7, iPadOS 26.7, iOS 27, iPadOS 27, macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7, and visionOS 27. This has not been independently confirmed by a second vendor source, and no vendor advisory text or workaround was supplied.

1. Immediate mitigations. No workaround is documented in the provided data. Until patched, reduce exposure by restricting users' ability to install and run untrusted sandboxed applications (enforce managed app allowlisting / MDM policy on iOS, iPadOS, macOS, and visionOS fleets), and restrict sideloading and untrusted developer installs. Because AV:L + UI:R, denying the user the ability to launch an attacker-supplied app removes the trigger condition.

2. Patch / upgrade steps. Update to the fixed releases: iOS 26.7 or 27; iPadOS 26.7 or 27; macOS Golden Gate 27; macOS Sequoia 15.8; macOS Tahoe 26.7; visionOS 27. Prioritize the macOS/iOS versions on devices that run third-party or internally developed apps. Verify build numbers after updating and track remediation via your MDM/compliance baseline (OS version >= the fixed builds above).

3. Long-term hardening. Treat these releases as part of the standard OS patch cadence; monitor for an official Apple security advisory and a corresponding CVE entry on NVD, because the current patch state rests on a single source. Continue enforcing app-notarization, sandbox-scoping, and least-privilege entitlements so that any single sandbox flaw has limited reach, and retain endpoint file-access telemetry so anomalous sandbox reads remain detectable.

References

• NVD — CVE-2026-84624: https://nvd.nist.gov/vuln/detail/CVE-2026-84624
• MITRE CWE-22 (Improper Limitation of a Pathname to a Restricted Directory / Path Traversal): https://cwe.mitre.org/data/definitions/22.html
• CISA Known Exploited Vulnerabilities Catalog (CVE-2026-84624 is NOT listed as of this report): https://www.cisa.gov/known-exploited-vulnerabilities-catalog
• Apple Security Releases (consult for the official advisory corresponding to iOS 26.7/27, macOS Sequoia 15.8, macOS Tahoe 26.7, visionOS 27): https://support.apple.com/en-us/HT201222
• FIRST EPSS (score 0.00168, 6.5th percentile): https://www.first.org/epss

Exploit-in-the-wild evidence: none. No public PoC, no exploit code, no Nuclei template, and no CISA KEV listing were provided; no threat-actor campaign is associated with this CVE in the available data.