CVE-2026-50604

Executive Summary

CVE-2026-50604 is an authentication-bypass vulnerability in the Acer Agent Service component bundled with NitroSense and PredatorSense. The socket handshake process does not properly require authentication before granting access to the service, allowing an unauthorized local connection to reach restricted functionality. Systems running the affected Acer software are exposed to unauthorized access, which may permit privilege escalation, service manipulation, or data disclosure.

Technical Analysis

CVE-2026-50604 is classified as CWE-306: Missing Authentication for Critical Function. The NVD description states that the Acer Agent Service component, included with NitroSense and PredatorSense, performs a socket handshake that does not properly require authentication before granting access to the service.

The core flaw is the absence of an authentication gate during the local socket handshake. A socket-based inter-process communication (IPC) endpoint is exposed by the Acer Agent Service. When a client connects and performs the handshake, the service grants access before verifying the identity or authorization of the caller. Because authentication is missing at this critical juncture, any process capable of reaching the socket — or, under certain circumstances as noted in the description, an unauthorized remote connection — can interact with service functionality that should be restricted.

The attack surface is the local socket endpoint. The description explicitly notes that "under certain circumstances, an unauthorized connection may be established." This suggests the socket may be reachable beyond the local loopback interface, or that local privilege boundaries are weak enough that an unprivileged process can access privileged service functionality. The exact binding (e.g., loopback vs. external interface), transport (e.g., TCP vs. named pipe), and protocol are not specified in the provided data; those implementation details remain unknown and should not be inferred beyond the plain description.

The impact is horizontal and vertical bypass of access controls. A caller that never authenticates obtains the same service access as a legitimate, authenticated client. This effectively removes the authorization boundary between unprivileged callers and the privileged operations performed by the Acer Agent Service. Because NitroSense and PredatorSense include hardware control, telemetry, and system-tuning functions, unauthorized access could permit manipulation of those functions.

No CVSS score, CWE subscore, EPSS value, or patch data are available for this CVE. No PoC, exploit code, or Nuclei template is publicly available. The patch confidence is 0/4, indicating that no patch evidence from any tracked source exists.

Exploitation Scenarios

No public PoC is available; the attack chain below is inferred strictly from the vulnerability class (CWE-306) and the NVD description.

1. Reconnaissance / target identification. An attacker identifies a host running NitroSense or PredatorSense with the Acer Agent Service active. The service exposes a local socket used for IPC. The attacker enumerates listening sockets and service processes to locate the endpoint.

2. Triggering the flaw class. The attacker connects to the Acer Agent Service socket. During the socket handshake, the service does not require authentication before granting access. The attacker does not provide credentials and is not required to do so; the missing authentication check (CWE-306) is the triggering condition.

3. Payload / execution method. At the vulnerability-class level, the attacker issues IPC requests to the service over the established unauthenticated connection. The description states that this "potentially allowing access to functionality that should be restricted." Specific message formats, command names, and payload structures are not disclosed in the available data and are not fabricated here.

4. Post-exploitation impact. Once access is granted, the attacker can invoke restricted service functionality. Depending on the privileges of the Acer Agent Service — which commonly runs with elevated system rights for hardware control — this may enable unauthorized configuration changes, privilege escalation, or manipulation of system tuning and telemetry features. The exact downstream effects are bounded by whatever operations the service exposes; those operations are not enumerated in the provided description.

The description's note that "under certain circumstances, an unauthorized connection may be established" leaves open the possibility that the socket can be reached by a non-local adversary, but the precise conditions are unspecified. No exploit-in-the-wild or threat-actor campaign is associated with this CVE in the provided data.

Impact Assessment

The vulnerability affects endpoint systems with Acer NitroSense and PredatorSense installed, where the Acer Agent Service is running. The blast radius is per-host but potentially high-severity, because the service typically executes with elevated privileges to manage hardware and system settings.

Business impact:

• Loss of access-control integrity on managed endpoints. Any unauthenticated local caller can reach restricted service functions.
• Potential privilege escalation on the host if the service exposes privileged operations to the unauthenticated caller.
• Potential unauthorized modification of hardware/performance settings, telemetry, or system configuration.
• Possible lateral movement if the socket is reachable from other hosts, though the exact reachability conditions are unspecified.

CVSS subscores: no authoritative CVSS score or vector was published (NVD score N/A; vector N/A). The operational vector supplied above (CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) is an analytical estimate reflecting local attack vector, no privileges, no user interaction, and high confidentiality, integrity, and availability impact; it is not a vendor or NVD rating and should be treated as provisional.

EPSS: not scored by FIRST.org at the time of writing. CISA KEV: not listed. No known exploitation in the wild is documented in the provided data.

Detection Guidance

Because no public PoC, exploit code, or Nuclei template exists, detection must focus on behavioral signals: unexpected processes connecting to the Acer Agent Service socket, anomalous IPC traffic to that endpoint, and unusual local connections to Acer-related services.

Sigma Rule

title: Potential Acer Agent Service Unauthenticated Socket Access (CVE-2026-50604)
id: 8f2c1a44-9c1e-4e2a-b0d1-7c3e5a91d2f0
status: experimental
description: Detects processes establishing connections to the Acer Agent Service socket used by NitroSense/PredatorSense, which may indicate exploitation of CVE-2026-50604 (missing authentication in socket handshake).
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-50604
author: valtersit.com
date: 2026-01-01
logsource:
  category: network_connection
  product: windows
detection:
  selection_process:
    Image|endswith:
      - '\\cmd.exe'
      - '\\powershell.exe'
      - '\\pwsh.exe'
      - '\\wscript.exe'
      - '\\cscript.exe'
      - '\\mshta.exe'
      - '\\rundll32.exe'
  selection_connection:
    DestinationPort: 0
    Initiated: 'true'
  condition: selection_process and selection_connection
falsepositives:
  - Legitimate management or diagnostic tools connecting to Acer services
level: medium
tags:
  - attack.t1210
  - cve.2026.50604

YARA Rule

rule CVE_2026_50604_Acer_Agent_Service_Strings
{
    meta:
        description = "Detects references to Acer Agent Service socket components associated with NitroSense/PredatorSense (CVE-2026-50604)."
        author = "valtersit.com"
        date = "2026-01-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-50604"
        cve = "CVE-2026-50604"

    strings:
        $s1 = "Acer Agent Service" ascii wide nocase
        $s2 = "NitroSense" ascii wide nocase
        $s3 = "PredatorSense" ascii wide nocase

    condition:
        uint16(0) == 0x5A4D and any of ($s*)
}

Suricata IDS Rule

alert tcp $HOME_NET any -> $HOME_NET any (msg:"CVE-2026-50604 Possible Acer Agent Service Unauthenticated Socket Access"; flow:to_server,established; content:"Acer Agent Service"; nocase; classtype:attempted-admin; reference:cve,2026-50604; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-50604; sid:2026506040; rev:1;)

Note: This rule targets the local-service socket pattern; adjust destination ports to the Acer Agent Service listener once identified in your environment.

Elastic Detection

network where destination.port > 0 and
  process.name in ("cmd.exe", "powershell.exe", "pwsh.exe", "wscript.exe", "cscript.exe", "mshta.exe", "rundll32.exe") and
  destination.ip in ("127.0.0.1", "::1")

This surfaces short-lived interpreter processes making loopback connections, a common pattern for interacting with a local privileged service socket.

Splunk SPL Query

index=* (source="XmlWinEventLog:Microsoft-Windows-Sysmon/Operational" OR source="WinEventLog:Security")
(EventCode=3 OR EventCode=5156)
| search (Image="*\\cmd.exe" OR Image="*\\powershell.exe" OR Image="*\\pwsh.exe" OR Image="*\\script.exe" OR Image="*\\mshta.exe" OR Image="*\\rundll32.exe")
| search (DestinationIp="127.0.0.1" OR DestinationIp="::1")
| stats count min(_time) as firstTime max(_time) as lastTime by Computer, Image, DestinationIp, DestinationPort
| where count > 0
| sort - count

Wazuh OSSEC Rule

<group name="acer,cve-2026-50604,">
  <rule id="100604" level="10">
    <if_sid>61603</if_sid>
    <field name="win.eventdata.destinationIp">127.0.0.1|::1</field>
    <field name="win.eventdata.image">cmd.exe|powershell.exe|pwsh.exe|wscript.exe|cscript.exe|mshta.exe|rundll32.exe$</field>
    <description>CVE-2026-50604: Suspicious process connected to loopback service possibly Acer Agent Service</description>
    <mitre>
      <id>T1210</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source). No vendor fix is available. The following measures reduce exposure until Acer publishes a fix.

Immediate mitigations:

• Disable or stop the Acer Agent Service on systems where NitroSense/PredatorSense functionality is not required.
• Restrict the service socket to a strict access-control list so only the intended, trusted client processes may connect.
• Isolate affected endpoints from untrusted local users and network segments; where feasible, block or firewall inter-host access to the service socket.
• Monitor for unexpected connections to the Acer service endpoint and alert on unauthenticated handshake patterns.

Patch/upgrade steps:

• Track Acer's advisory channel for NitroSense and PredatorSense updates. No patch or fixed version has been identified as of this writing.
• Once a vendor fix is released, validate it against a test system before fleet-wide deployment and verify that an authentication requirement has been introduced into the socket handshake.

Long-term hardening:

• Enforce peer authentication on all local IPC endpoints; do not rely on socket reachability as an access-control boundary.
• Apply least privilege to OEMS agent services; avoid running them with system-level rights where not strictly necessary.
• Maintain a software inventory of OEM utilities and remove unnecessary preinstalled agents.
• Continuously assess OEM-supplied services with attack-surface monitoring and authenticated vulnerability scanning.

References

• NVD — CVE-2026-50604: https://nvd.nist.gov/vuln/detail/CVE-2026-50604
• MITRE CWE-306 — Missing Authentication for Critical Function: https://cwe.mitre.org/data/definitions/306.html
• MITRE ATT&CK T1210 — Exploitation of Remote Services: https://attack.mitre.org/techniques/T1210/
• CISA Known Exploited Vulnerabilities Catalog (CVE-2026-50604 not listed as of writing): https://www.cisa.gov/known-exploited-vulnerabilities-catalog
• FIRST EPSS (not yet scored): https://www.first.org/epss/

No public PoC, exploit code, Nuclei template, or threat-actor campaign is associated with this CVE in the available data.