CVE-2026-89172

Executive Summary

CVE-2026-89172 is a CWE-1300 (Improper Protection of Physical Side Channels) vulnerability affecting Microchip application notes AN1044 and AN953 and software deliverable SW300052. The issue permits an attacker with physical access to the target hardware to observe physical emanations or measurable characteristics of the device, potentially recovering sensitive material processed by the referenced implementations. Affected deployments are typically embedded, firmware-driven products built on Microchip reference designs; because no patch, workaround, or public exploit data is currently available, exposure is best mitigated through physical-access controls and vendor engagement.

Technical Analysis

The NVD description states: "Improper protection of physical side channels vulnerability in Microchip AN1044, Microchip AN953, and Microchip SW300052. This issue affects AN1044: through A; AN953: through A; SW300052: through 2.6."

The assigned weakness, CWE-1300 "Improper Protection of Physical Side Channels," classifies this issue as a hardware/embedded-implementation flaw in which an attacker exploits observable physical characteristics rather than a software protocol defect. Side-channel leakage in this class generally falls into categories such as timing, power consumption, electromagnetic emanation, or other measurable physical phenomena that correlate with secret-dependent processing. Because the NVD description does not disclose which specific side channel is affected, which secret material is at risk, or which code paths in AN1044/AN953/SW300052 are implicated, the precise mechanism cannot be asserted here. The only verifiable technical facts are: (1) the flaw is a physical side-channel protection deficiency, (2) it is present through the specified revisions of the three Microchip deliverables, and (3) no CVSS vector, CWE detail beyond the class identifier, or code-level advisory has been published in the supplied data.

Attack surface considerations for this vulnerability class: exploitation requires a physical-access or closely-coupled-observation capability against the device running the affected implementation. This is consistent with an attacker who has device possession (lost/stolen unit, intercepted shipment, repair-channel access, or an insider within a manufacturing/provisioning environment) or who can place measurement equipment in proximity to a fielded device. Remote, network-based exploitation is not implied by the vulnerability class or by the description. Application notes (AN1044, AN953) are reference implementations distributed to customers; therefore, the vulnerable code or design pattern may have been propagated into third-party products that incorporate these designs — expanding the affected population beyond Microchip itself to downstream OEMs. SW300052 is referenced as a software deliverable with revisions "through 2.6," indicating that firmware/software artifacts — not only documentation — carry the flaw. This raises the likelihood that the vulnerable implementation ships in fielded devices, though the provided data contains no package inventory, binary identifiers, or OSV package mapping to confirm affected product SKUs.

No function names, file paths, cryptographic routine names, or register/memory details are present in the supplied CNA title or NVD description; accordingly, none are asserted in this report. Insufficient technical detail is available to describe the exact leakage mechanism, the targeted asset (e.g., key material vs. intermediate state), or the number of measurements required for key recovery. Analysts should treat the vulnerability class — not a published exploit technique — as the basis for threat modeling until the vendor publishes an advisory.

Exploitation Scenarios

No public PoC, exploit code, or Nuclei template is available for CVE-2026-89172. The following chain is inferred strictly from the vulnerability class (CWE-1300, physical side channel) and must be treated as a class-level model, not a described exploit.

1. Reconnaissance / target identification. The attacker identifies a target device or shipment known to implement the affected Microchip deliverables — AN1044, AN953 (through revision A), or firmware/software built on SW300052 through 2.6. Identification may rely on product documentation, firmware version strings, or procurement records. Because the flaw is physical, reconnaissance centers on gaining custody of, or authorized proximity to, an affected unit rather than on scanning a network perimeter.

2. Triggering the flaw class. With the device in hand or within reach, the attacker exercises the device's normal operation — for example, initiating the operation that processes secret-dependent data — while applying a physical measurement technique appropriate to the leaked channel (the specific channel is not disclosed in the supplied data). The improper protection means that observable physical behavior varies with the secret-dependent computation, unlike a hardened implementation that would be designed to mask or decouple such variation.

3. Observation / data collection. The attacker records the physical observables across repeated executions of the target operation. In side-channel classes such as timing, power, or electromagnetic analysis, repeated trace capture and statistical processing are used to correlate observables with secret-dependent state. The supplied description does not specify the collection method, sample volume, or whether the leakage is exploitable in a single trace or requires many, so no quantitative claim is made here.

4. Post-exploitation impact. Successful exploitation of a physical side channel typically results in disclosure of sensitive material (confidentiality impact) — for example, embedded secrets used by the affected implementation. There is no indication in the provided data of integrity or availability impact. Because there is no published CVSS vector, no quantitative impact score can be cited; the provisional vector in METADATA (AV:P/AC:H, C:H) is an analytical inference consistent with the physical side-channel class and should be validated against the eventual vendor advisory.

Threat-actor relevance: CISA KEV status is NO, and no exploit-in-the-wild evidence accompanies this CVE. The realistic adversary profiles are physical-access actors: device thieves, supply-chain interceptors, counterfeit/refurbishment operations, and hardware-focused researchers. There is no evidence in the supplied data tying this CVE to a named campaign or APT group.

Impact Assessment

Business impact is concentrated in confidentiality of embedded secrets for organizations that field products built on the affected Microchip designs. Blast radius depends on how widely AN1044, AN953, and SW300052 have been integrated by downstream OEMs — a population not enumerable from the supplied data. Because the required vector is physical and the attack complexity for side-channel extraction is generally non-trivial, the practical risk to remotely exposed systems is low; the risk to devices in adversary custody (shipping, RMA, repair, retail theft) is materially higher. Affected asset classes plausibly include embedded controllers, security tokens/authentication devices, and any firmware lineage derived from the referenced application notes, but the supplied data does not enumerate specific products.

CVSS subscores: No official CVSS score or vector was published with this CVE (NVD CVSS: N/A). The provisional vector in METADATA — CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N — is an analyst inference for a physical side-channel disclosure and is provided only to support prioritization. Under that provisional model, the only impacted metric is Confidentiality (High); Integrity and Availability are unaffected, Scope is Unchanged, and the physical attack vector plus high complexity keeps the base score in a moderate band. Organizations must not treat this inferred score as authoritative; re-score when the vendor advisory or NVD enrichment appears. EPSS has not been scored by FIRST.org, and no exploitation likelihood estimate should be assumed.

Detection Guidance

Detection for a physical side-channel flaw is inherently partial: the exploitation step does not traverse the network and may not leave host telemetry. The controls below target the observable proxies — inventory of affected versions, tamper indicators, provisioning/test-mode abuse, and anomalous physical-access workflows — and should be tuned to the environment. No IOCs are furnished by the vendor because none exist for this vulnerability class.

Sigma Rule

title: Suspicious Access to Microchip AN1044/AN953/SW300052 Artifacts or Provisioning Tools
id: 8f0c2f5e-9b3a-4d7c-a1e2-00000089172
status: experimental
description: Detects file, process, or registry activity referencing Microchip AN1044, AN953, or SW300052 artifacts, which may indicate an actor staging side-channel analysis tooling or interacting with an affected implementation.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-89172
author: valtersit.com Threat Intelligence
date: 2026/01/01
logsource:
  category: process_creation
  product: windows
detection:
  selection_artifact:
    CommandLine|contains:
      - 'AN1044'
      - 'AN953'
      - 'SW300052'
  selection_tooling:
    Image|endswith:
      - '\chipwhisperer.exe'
      - '\logic.exe'
      - '\pulseview.exe'
      - '\sigrok-cli.exe'
  condition: selection_artifact and selection_tooling
falsepositives:
  - Authorized hardware security evaluation or lab testing
  - Vendor firmware update utilities during approved maintenance
level: medium
tags:
  - attack.t1195
  - attack.t1200
  - cve.2026.89172

YARA Rule

rule CVE_2026_89172_Microchip_SideChannel_Artifacts
{
    meta:
        author = "valtersit.com Threat Intelligence"
        description = "Detects firmware/artifact strings associated with Microchip AN1044, AN953, SW300052 affected through the specified revisions (CVE-2026-89172)"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-89172"
        date = "2026-01-01"
        severity = "medium"

    strings:
        $an1044 = "AN1044" ascii wide nocase
        $an953  = "AN953"  ascii wide nocase
        $sw     = "SW300052" ascii wide nocase

    condition:
        uint16(0) == 0x5A4D or   // PE image
        uint32(0) == 0x464C457F or // ELF image
        uint32be(0) == 0x7F454C46
        // fall through to string-only match for raw dumps
        or any of them
}

Note: The above YARA rule keys on the documented deliverable identifiers. It is a triage aid for artifact discovery only; it does not detect side-channel exploitation, which is a physical phenomenon.

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-89172 Possible Recon for Microchip AN1044/AN953/SW300052 Artifacts"; flow:to_server,established; http.header; content:"User-Agent"; content:"AN1044"; nocase; http.header; content:"User-Agent"; content:"AN953"; nocase; http.header; content:"User-Agent"; content:"SW300052"; nocase; classtype:attempted-recon; sid:202689172; rev:1; metadata:created_at 2026_01_01, reference cve.2026.89172;)

Note: This rule targets opportunistic web reconnaissance for the affected deliverable names, not the side-channel attack itself (which produces no network traffic). Expect false positives from legitimate documentation searches.

Elastic Detection

process where event.type == "start" and
  (process.command_line : "*AN1044*" or
   process.command_line : "*AN953*"  or
   process.command_line : "*SW300052*") and
  (process.command_line : "*dump*" or
   process.command_line : "*trace*" or
   process.command_line : "*capture*" or
   process.name : ("sigrok-cli*", "pulseview*", "logic*", "chipwhisperer*"))

Analyst note: Correlate hits with physical-access events (badge logs, lab bookings, RMA intake) to raise fidelity. Isolation-forest a broad file or network query only if firmware update tooling for the affected parts is known to be present.

Splunk SPL Query

index=endpoint OR index=firmware OR index=asset_inventory
| eval needle=lower(_raw)
| where match(needle,"an1044") OR match(needle,"an953") OR match(needle,"sw300052")
| eval is_tooling=if(match(needle,"dump") OR match(needle,"trace") OR match(needle,"capture") OR match(needle,"sigrok") OR match(needle,"chipwhisperer"),"yes","no")
| stats count min(_time) as first_seen max(_time) as last_seen values(host) as hosts values(user) as users by is_tooling
| where is_tooling="yes" OR count > 20
| sort - count

Purpose: surfaces clustered references to affected deliverable strings co-occurring with side-channel capture terminology, or anomalous reference volume that may indicate staging.

Wazuh OSSEC Rule

<group name="microchip,cve-2026-89172,">
  <rule id="100891" level="7">
    <if_sid>550</if_sid>
    <match>AN1044|AN953|SW300052</match>
    <description>CVE-2026-89172: Reference to affected Microchip deliverable (AN1044/AN953/SW300052) detected on host - possible side-channel attack staging.</description>
    <mitre>
      <id>T1195</id>
      <id>T1200</id>
    </mitre>
    <group>physical_side_channel,</group>
  </rule>

  <rule id="100892" level="10">
    <if_sid>100891</if_sid>
    <match>sigrok|chipwhisperer|pulseview|trace|capture|dump</match>
    <description>CVE-2026-89172: Affected Microchip deliverable reference co-occurring with capture/trace tooling - escalate to hardware security team.</description>
    <group>physical_side_channel,escalate,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 — UNPATCHED. No patch, hotfix, firmware revision, or vendor advisory has been identified from any tracked source. The version ranges in the NVD description (AN1044 through A; AN953 through A; SW300052 through 2.6) should be treated as affected and currently unresolved. Vendor fix: N/A. Workarounds: N/A from the vendor — the mitigations below are compensating controls, not fixes.

1. Immediate mitigations

• Restrict and log physical access to systems and field devices built on AN1044, AN953, or SW300052. Enforce chain-of-custody for shipments, RMA/repair intake, and lab benches where affected units are powered and operated.
• Treat device-in-custody scenarios (loss, theft, interception) as potential secret-compromise events; rotate any device-resident secrets where rotation is supported.
• Limit who may run provisioning, test-mode, or debug interfaces on affected hardware; disable debug/test modes in production units where the design permits.
• Inventory downstream products and firmware lineages derived from the referenced Microchip application notes to establish true blast radius.

2. Patch / upgrade steps

• Contact Microchip support and monitor the Microchip product security advisory channel for the CVE-2026-89172 advisory and corrected revisions of AN1044, AN953, and SW300052. Because no patch evidence exists, do not assume any specific revision is fixed.
• Once a vendor advisory is published, map affected revisions to the corrected revision, obtain the corrected application-note/firmware deliverable, and re-validate any downstream OEM product that incorporated the vulnerable design.
• Track NVD (https://nvd.nist.gov/vuln/detail/CVE-2026-89172) for enrichment: CVSS vector, CWE confirmation, and any reference URLs.

3. Long-term hardening

• Adopt side-channel-resistant design practices for secret-dependent code paths in embedded products, including constant-time or masked implementations where applicable, and require side-channel evaluation (e.g., leakage assessment) in hardware acceptance testing.
• Maintain an authoritative firmware/software bill of materials (SBOM) across OEM supply chains so that a future advisory against AN1044/AN953/SW300052 can be triaged rapidly.
• Include physical-access threat models in security reviews for token/authentication devices and other products that store long-lived secrets.

References

• NVD — CVE-2026-89172: https://nvd.nist.gov/vuln/detail/CVE-2026-89172
• CWE-1300 — Improper Protection of Physical Side Channels: https://cwe.mitre.org/data/definitions/1300.html
• Microchip Product Security / CVE advisories portal (consult for the eventual CVE-2026-89172 advisory): https://www.microchip.com/en-us/support/design-help/product-security
• CISA Known Exploited Vulnerabilities Catalog (verify status; CISA KEV = NO for this CVE as of this report): https://www.cisa.gov/known-exploited-vulnerabilities-catalog
• FIRST EPSS (no score assigned as of this report): https://www.first.org/epss/

Threat actor / exploit-in-the-wild note: No public PoC, exploit code, or Nuclei template exists for CVE-2026-89172 in the supplied data, CISA KEV status is NO, and no named threat-actor campaign is associated with this CVE. All exploitation content in this report is an inference from the CWE-1300 vulnerability class and must not be represented as observed activity.