CVE-2026-58005

Executive Summary

CVE-2026-58005 is an out-of-bounds read vulnerability (CWE-119) in Altera Trusted Firmware running on the Hard Processor System (HPS) of Altera SoC FPGA devices, affecting builds through socfpga_v2.14.0. Because the affected component executes at the highest privilege level of the platform (secure monitor / EL3-equivalent firmware), a successful out-of-bounds read that also overflows an adjacent buffer can translate directly into privilege escalation across trust boundaries, yielding high integrity and availability impact (CVSS 8.1). No public proof-of-concept, exploit code, or Nuclei template exists at time of writing, and no vendor patch has been published.

Technical Analysis

The NVD description states the defect class precisely but briefly: an out-of-bounds read in Altera Trusted Firmware on HPS that allows Privilege Escalation and Overflow Buffers. This is classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer), the parent weakness class covering both out-of-bounds reads and writes.

Key architectural facts that can be derived from the description:

• Attack surface / placement. The affected code is Trusted Firmware executing on the HPS (Hard Processor System) within an Altera SoC FPGA. Trusted Firmware in this class of platform runs in the most privileged exception level and implements the secure monitor, Power State Coordination Interface (PSCI), secure-world service dispatch, and the interface between the secure and non-secure worlds.
• Vulnerability mechanism (class-level). An out-of-bounds read means the code computes or consumes an index, length, or offset without adequately validating it against the size of the source buffer. The read itself discloses or consumes adjacent memory. The description further indicates an "Overflow Buffers" consequence — i.e., the same flawed bounds handling can cause data to be written past the end of a destination buffer. In trusted-firmware contexts, OOB reads and buffer overflows most commonly arise from processing attacker-influenced structured input: inter-processor or secure-world request messages where a length/offset field is trusted rather than validated against the actual payload or the destination buffer capacity.
• Trust boundary. Because the vulnerable code runs in the trusted/secure firmware layer, an OOB condition is not merely an application-level bug. Memory contents accessed by this code can include secure-state data, and corruption of adjacent buffers in that context crosses a C/I/A privilege boundary — which is why the CVSS vector sets Scope:Changed (S:C).

What is not known and must not be assumed. The provided description does not name any specific function, command, message opcode, API path, file, or parameter. No CVE-specific code location, calling convention, or exact input field is given. Any claim about "the exact function that mishandles X" would be fabrication. Analysis at this stage must therefore remain at the vulnerability-class level: this is a memory-safety failure (insufficient bounds validation on an attacker-influenceable read, with an associated buffer-overflow outcome) inside privileged firmware.

CVSS interpretation (from the given vector). AV:L (local access required), AC:L (no special conditions beyond reachability), PR:H (the attacker must already hold privileged access on the host/non-secure side to reach the interface), UI:N (no victim interaction), S:C (impact escapes the vulnerable component's security scope), C:L (limited confidentiality — partial/incomplete memory disclosure), I:H (high integrity impact — buffer overflow can corrupt firmware or secure state), A:H (high availability impact — corruption in trusted firmware can crash or wedge the platform). The 8.1 base score is consistent with a local, privileged-trigger, high-impact memory-safety flaw.

Reachability constraint matters. With PR:H and AV:L, this is not remotely exploitable on its own; the flaw is a privilege-escalation primitive usable by an attacker who already operates on the non-secure side or on a privileged local interface to climb into the trusted firmware domain (or to destabilize it).

Exploitation Scenarios

No public PoC or exploit code is available; the following attack chain is inferred strictly from the vulnerability class and the CVSS vector.

1. Reconnaissance / target identification. An attacker first identifies a target platform running Altera SoC FPGA hardware (HPS) with Trusted Firmware builds at or below socfpga_v2.14.0. This is confirmed by reading firmware/version banners exposed through the non-secure OS, device-tree or driver version strings, or by the presence of the SoC FPGA vendor strings. Shodan dorks in METADATA target these exposed identifiers where firmware/boot artifacts are network-adjacent.

2. Precondition establishment (PR:H). Because the vector requires high privileges locally, the adversary must already hold privileged code execution on the non-secure side (e.g., root on the application processor OS) or access to a privileged interface that reaches the trusted firmware service boundary.

3. Triggering the flaw (class-level). The attacker submits crafted input through whichever non-secure→trusted-firmware interface invokes the affected code path. Because the weakness is an out-of-bounds read with buffer-overflow consequences, the crafted input is designed so that the firmware's bounds check fails to constrain a length/offset before the data is read (causing disclosure of adjacent memory) and/or written (causing overflow). The exact message format, opcode, or parameter is not specified in the available data and must be determined by the attacker through reverse engineering of the specific firmware image — no public detail exists.

4. Post-exploitation impact. Successful triggering yields three adverse outcomes consistent with the CVSS subscores: (a) Confidentiality: Low — the OOB read discloses adjacent secure-context memory; (b) Integrity: High — the buffer overflow corrupts adjacent trusted-firmware data, enabling control-flow or state manipulation in the privileged domain; (c) Availability: High — corruption in trusted firmware can crash, hang, or render the platform unstable, including secure-world services.

Impact Assessment

• Business impact. Altera SoC FPGA platforms are used in embedded, industrial, networking, and defense-adjacent roles. A memory-safety flaw in the trusted firmware layer undermines the hardware root of trust on these devices. Compromise of trusted firmware can defeat secure boot and the isolation between secure and non-secure worlds for the life of the device, potentially requiring full firmware reflash or hardware replacement.
• Affected systems. Devices running Altera Trusted Firmware on HPS at versions through socfpga_v2.14.0. The exact downstream product list is not provided in the source data.
• Blast radius / scope. Scope:Changed (S:C) indicates impact extends beyond the vulnerable firmware component into the wider platform. A single trigger can affect both the secure and non-secure worlds.
• Subscore-driven risk profile. PR:H and AV:L temper remote risk, but I:H and A:H in a trusted component elevate the severity for defenders: this is a high-value escalation primitive for an attacker already inside the perimeter, and a high-value denial-of-service vector against the security subsystem.
• Exploitability. EPSS not yet scored by FIRST.org; CISA KEV: NO; no public PoC. Current observed exploitation risk is low, but impact, if achieved, is high.

Detection Guidance

Detection here centers on integrity of the trusted-firmware image and on anomalous access patterns to the secure-monitor interfaces — there is no exploit traffic to signature, so detections are behavioral and post-condition focused.

Sigma Rule

title: Altera SoC FPGA Trusted Firmware Unexpected Version or Modification Activity
id: 0d2b9e5c-5800-4c4a-9c1f-000058005a01
status: experimental
description: Detects access, enumeration, or modification of Altera SoC FPGA Trusted Firmware artifacts consistent with CVE-2026-58005 target reconnaissance or tampering
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-58005
author: valtersit.com
date: 2026/01/01
logsource:
  category: file_event
  product: linux
detection:
  selection_paths:
    - '/lib/firmware/*'
    - '/boot/*'
    - '/sys/firmware/*'
    - '/dev/*socfpga*'
  selection_keywords:
    CommandLine|contains:
      - 'socfpga'
      - 'trusted-firmware'
      - 'atf'
      - 'hps'
      - 'dd if='
      - 'flash_erase'
  condition: selection_paths or selection_keywords
fields:
  - CommandLine
  - Image
  - TargetFilename
falsepositives:
  - Legitimate firmware update utilities and vendor flashing tools
level: medium
tags:
  - attack.privilege_escalation
  - attack.t1068
  - cve.2026.58005

YARA Rule

rule CVE_2026_58005_Altera_TrustedFirmware_Memory_Safety_Recon
{
    meta:
        author = "valtersit.com"
        description = "Hunts firmware images / blobs referencing Altera SoC FPGA Trusted Firmware HPS builds for CVE-2026-58005 triage"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-58005"
        date = "2026-01-01"
        severity = "high"

    strings:
        $ver1 = "socfpga_v2.14.0" ascii wide nocase
        $ver2 = "socfpga_v2." ascii wide nocase
        $tf1  = "Trusted Firmware" ascii wide nocase
        $tf2  = "ATF" ascii wide
        $hps  = "HPS" ascii wide
        $plt  = "Altera" ascii wide nocase

    condition:
        uint32(0) == 0x464C5348 or  // heuristic: not all images are flat; combine name and string signals
        (2 of ($ver*, $tf*)) or (1 of ($tf*) and 1 of ($hps, $plt))
}

Suricata IDS Rule

alert tcp any any -> any any (msg:"CVE-2026-58005 Altera SoC FPGA Trusted Firmware reconnaissance/version probe"; flow:to_server,established; content:"socfpga"; nocase; content:"v2."; nocase; distance:0; within:16; sid:202658005; rev:1; metadata:cve CVE-2026-58005, affected_product Altera_Trusted_Firmware; classtype:attempted-recon; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-58005;)

Note: CVE-2026-58005 is triggered over a local (AV:L), privileged (PR:H) interface and has no network-facing exploit primitive; the Suricata rule above only provides weak reconnaissance signal on network-adjacent version strings and should be treated as low-fidelity.

Elastic Detection

process where event.type in ("start", "end") and
  (
    process.command_line : ("*socfpga*", "*trusted-firmware*", "*flash_erase*", "*dd if=*firmware*") or
    process.executable : ("*/usr/bin/flashcp*", "*/usr/sbin/flash_erase*")
  ) and
  process.parent.name : ("sh", "bash", "systemd", "init")

Splunk SPL Query

index=linux sourcetype=linux_secure OR sourcetype=linux_audit (CommandLine=*socfpga* OR CommandLine=*trusted-firmware* OR CommandLine=*hps* OR file_path="*/lib/firmware/*" OR file_path="*/boot/*")
| stats count min(_time) as first_seen max(_time) as last_seen values(CommandLine) as cmds by host user file_path
| where count > 0
| convert ctime(first_seen) ctime(last_seen)
| sort - count

Wazuh OSSEC Rule

<group name="altera_socfpga,cve_2026_58005,">
  <rule id="100580" level="10">
    <decoded_as>json</decoded_as>
    <field name="CommandLine">\.*(socfpga|trusted-firmware|flash_erase|hps).*</field>
    <description>CVE-2026-58005: Altera SoC FPGA Trusted Firmware access or tampering activity detected</description>
    <mitre>
      <id>T1068</id>
    </mitre>
    <group>privilege_escalation,</group>
  </rule>
  <rule id="100581" level="12">
    <if_sid>100580</if_sid>
    <field name="CommandLine">\.*(dd if=|flash_erase|mtd write).*firmware.*</field>
    <description>CVE-2026-58005: Possible trusted-firmware modification on Altera HPS</description>
    <group>integrity_monitoring,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source). There is no vendor fix, no version-fixed reference, and no workaround published in the source data. The version boundary is documented as "through socfpga_v2.14.0," meaning no fixed release is identified.

1. Immediate mitigations (compensating controls).

   • Treat these devices as exposed to a local privileged escalation primitive; enforce strict least privilege on the non-secure side so that PR:H preconditions are hard to meet (no unnecessary root, no unnecessary access to firmware or secure-monitor interfaces).
   • Restrict and monitor access to firmware partitions, JTAG/debug interfaces, and any non-secure→secure service interface; disable debug interfaces in production where feasible.
   • Hash and monitor the trusted-firmware image for unauthorized modification (integrity monitoring), and log boot-time firmware version strings to detect downgrades.
   • Apply network segmentation and monitoring to reduce reachability of affected embedded platforms (see Suricata rule above).

2. Patch / upgrade steps.

   • Monitor Altera's public security advisory channels and the Trusted Firmware SoC FPGA source tree for a fixed release newer than socfpga_v2.14.0.
   • When a fix is published: verify it against the affected version boundary, rebuild/refresh Trusted Firmware, and re-flash affected devices following vendor guidance. Because this is unpatched, no fixed version can be recommended at this time.

3. Long-term hardening.

   • Enable secure boot with verified image signatures, and require signed firmware updates to prevent downgrade to a vulnerable build.
   • Adopt a memory-safety review process and fuzzing (language/format-aware) for trusted-firmware input-handling code paths on HPS.
   • Maintain a firmware SBOM and version inventory so affected units can be located quickly.
   • Subscribe to NVD/CNA feeds for Altera Trusted Firmware to obtain the eventual CVE update, patch reference, and any EPSS/KEV reclassification.

References

• NVD — CVE-2026-58005: https://nvd.nist.gov/vuln/detail/CVE-2026-58005
• CWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer: https://cwe.mitre.org/data/definitions/119.html
• MITRE ATT&CK T1068 — Exploitation for Privilege Escalation: https://attack.mitre.org/techniques/T1068/
• Trusted Firmware project (upstream source for SoC FPGA trusted firmware): https://www.trustedfirmware.org/
• Altera security advisories (monitor for the eventual fix release after socfpga_v2.14.0): https://www.altera.com/

Threat actor campaigns / exploit-in-the-wild: none reported. CISA KEV: NO. EPSS: not yet scored by FIRST.org. No public PoC, exploit code, or Nuclei template available at time of writing.