CVE-2026-13467

Executive Summary

CVE-2026-13467 is an out-of-bounds write vulnerability in Altera Trusted Firmware running on the Hard Processor System (HPS) of Intel/Altera SoC FPGA devices, affecting versions through socfpga_v2.14.0. This flaw allows a local attacker with high privileges to corrupt memory due to improper memory protection implementation, potentially leading to privilege escalation, code execution, or system compromise within the trusted execution environment. With a CVSS score of 8.1, this vulnerability poses a significant risk to industrial control systems, embedded devices, and secure boot chains relying on the affected firmware.

Technical Analysis

CVE-2026-13467 is classified as an out-of-bounds write (CWE-787) in Altera Trusted Firmware on the HPS. The vulnerability arises from the improper configuration or implementation of memory protections, allowing a write operation to occur beyond the intended buffer boundaries. Trusted Firmware on HPS is a secure monitor that runs at the highest privilege level (EL3), responsible for secure boot, runtime services, and isolation between secure and non-secure worlds. An out-of-bounds write at this privilege level can corrupt adjacent memory structures, including page tables, secure world data, or control flow metadata. The CVSS vector indicates local access (AV:L), low attack complexity (AC:L), high privileges required (PR:H), no user interaction (UI:N), and a changed scope (S:C), meaning the vulnerability can impact resources beyond the vulnerable component. The integrity impact is high (I:H) and availability impact is high (A:H), while confidentiality impact is low (C:L). The affected version range is through socfpga_v2.14.0, and no patch is currently available.

Exploitation Scenarios

1. Reconnaissance/Target Identification: An attacker identifies a target device running Altera SoC FPGA with Trusted Firmware on HPS, version through socfpga_v2.14.0. This could be achieved through network scanning for HPS management interfaces or by gaining local access via other means (e.g., compromised OS running on the HPS).
2. Triggering the Flaw: The attacker, already possessing high privileges (e.g., root in the non-secure world or a malicious secure world component), crafts a request or input that causes the Trusted Firmware to perform a write operation beyond the allocated buffer. The specific input vector is not detailed in the available description; however, it likely involves a command or service exposed by the Trusted Firmware that improperly validates memory boundaries.
3. Payload/Execution: The out-of-bounds write can be used to overwrite critical data structures, such as function pointers or return addresses, within the Trusted Firmware's context. This could lead to arbitrary code execution at EL3, the highest privilege level. The absence of a public PoC means the exact payload structure is unknown, but it would follow typical memory corruption exploitation techniques adapted to the secure monitor environment.
4. Post-Exploitation Impact: Successful exploitation grants the attacker control over the secure world, allowing them to disable secure boot, exfiltrate secrets (e.g., encryption keys), persist in firmware, or pivot to attack other components of the SoC. The changed scope (S:C) indicates the attacker can affect resources beyond the Trusted Firmware, such as the operating system or other hardware components.

Impact Assessment

The CVSS score of 8.1 reflects a high-severity vulnerability with significant integrity and availability impacts. The local attack vector and high privileges required limit the initial attack surface, but the changed scope means the blast radius extends beyond the Trusted Firmware. Affected systems include industrial control systems, automotive, aerospace, and other embedded platforms using Altera SoC FPGAs with HPS and Trusted Firmware. A successful exploit could lead to full device compromise, persistent backdoors, and lateral movement within a network. The confidentiality impact is low, as the primary risk is integrity and availability.

Detection Guidance

Sigma Rule

title: Altera Trusted Firmware Out-of-Bounds Write Exploitation Attempt
id: 1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects potential exploitation of CVE-2026-13467 via abnormal memory write patterns or unauthorized access to Trusted Firmware interfaces.
author: Senior Cybersecurity Analyst
date: 2026-01-01
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith: '/dev/mem'
        CommandLine|contains: 'socfpga'
    condition: selection
falsepositives:
    - Legitimate firmware updates
level: high

YARA Rule

rule CVE_2026_13467_Altera_Trusted_Firmware
{
    meta:
        description = "Detects potential exploitation of CVE-2026-13467 in Altera Trusted Firmware"
        author = "Senior Cybersecurity Analyst"
        date = "2026-01-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-13467"
        severity = "high"
    strings:
        $socfpga = "socfpga_v2.14.0" ascii wide
        $tf = "Trusted Firmware" ascii wide
    condition:
        any of them
}

Suricata IDS Rule

alert tcp any any -> any any (msg:"CVE-2026-13467 Altera Trusted Firmware Out-of-Bounds Write Attempt"; flow:to_server; content:"socfpga"; http_uri; classtype:attempted-admin; sid:1000001; rev:1;)

Elastic Detection

process where process.name == "/dev/mem" and process.args : "*socfpga*"

Splunk SPL Query

index=main sourcetype=linux_secure "socfpga" OR "Trusted Firmware" | stats count by host, user, process

Wazuh OSSEC Rule

<rule id="100001" level="12">
    <decoded_as>syslog</decoded_as>
    <match>socfpga</match>
    <description>CVE-2026-13467: Potential Altera Trusted Firmware exploitation attempt</description>
    <mitre>
        <id>T1068</id>
    </mitre>
</rule>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source).

1. Immediate Mitigations: Restrict local access to HPS management interfaces to trusted users only. Monitor for abnormal memory access patterns targeting Trusted Firmware. Apply hardware-based memory protection mechanisms if available. Isolate affected devices on segmented networks.
2. Patch/Upgrade Steps: No patch is currently available. Monitor Altera/Intel security advisories for updates beyond socfpga_v2.14.0. Once a patched version is released, validate and deploy it following secure update procedures.
3. Long-term Hardening: Implement secure boot with measured boot to detect firmware tampering. Use runtime integrity monitoring for Trusted Firmware. Conduct regular security audits of firmware code. Apply principle of least privilege to all HPS interfaces.

References

• NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-13467
• Altera Security Advisories: https://www.intel.com/content/www/us/en/security-center/default.html
• CWE-787: https://cwe.mitre.org/data/definitions/787.html
• MITRE ATT&CK T1068: https://attack.mitre.org/techniques/T1068/
• No known threat actor campaigns or exploit-in-the-wild evidence at this time.