CVE-2026-4930: DPA bypass weakens hardware crypto

CISO Take

This CVE describes a hardware-level flaw in SYMCRYPTO, the crypto acceleration engine on Silicon Labs' SiXG301 chip, where an attacker who already has code execution on the device can force weak seed values into the engine's differential power analysis (DPA) countermeasures, reducing their entropy and making loaded cryptographic keys easier to extract via power-analysis side channels. Despite the platform's "ml_library" tag in this feed, nothing in the advisory ties this to any AI/ML framework, model, or pipeline — it is a silicon/firmware secure-element issue on an IoT-class chip, and the classification appears to be a categorization artifact rather than a genuine AI attack surface. Exploitability is low on paper (EPSS 0.00101, effectively near the bottom of the scoring range despite the percentile label, no public exploit, no KEV listing, CISA SSVC decision is TRACK) and the attack requires an attacker to already have code execution — this is a post-compromise key-extraction technique, not an initial-access vector. For most security teams this warrants no urgent action beyond standard vendor patch tracking; the only reason to care is if your fleet uses SiXG301-based devices (e.g., embedded/IoT gateways) for key storage or secure boot, in which case you should check Silicon Labs' advisory (community.silabs.com/068Vm00000sjHs3) for firmware updates and treat it as a defense-in-depth/supply-chain hardware issue rather than an AI security incident.

Sources: NVD EPSS community.silabs.com

What is the risk?

Low urgency overall: exploitation requires an attacker to already hold code execution on the target device, which is a high bar and limits this to a post-compromise privilege/persistence technique (key extraction) rather than a remotely exploitable entry point. EPSS is 0.00101 (near-negligible predicted exploitation activity), there is no public exploit code, no Nuclei template, and it is not in CISA KEV; CISA's own SSVC decision is TRACK (monitor, no urgent action). The realistic risk is narrow and specific to environments that rely on SYMCRYPTO's DPA countermeasures for physical/side-channel key protection — largely a hardware supply-chain and embedded-systems concern.

How does the attack unfold?

Prerequisite: local code execution

Attacker obtains code execution capability on the device hosting the SiXG301 chip, a precondition for this vulnerability rather than the vulnerability itself.

DPA countermeasure weakening

Attacker forces specific seed values into SYMCRYPTO's DPA countermeasure logic via the PSA crypto library interface, reducing entropy that normally masks power-trace leakage.

Side-channel key extraction

Attacker performs differential power analysis while the weakened engine processes AES/hashing operations, statistically recovering the loaded cryptographic key.

Impact: key compromise

Extracted keys enable decryption of protected data, firmware forgery, or device impersonation downstream of the compromised secure element.

Prerequisite: local code execution

Attacker obtains code execution capability on the device hosting the SiXG301 chip, a precondition for this vulnerability rather than the vulnerability itself.

DPA countermeasure weakening

Attacker forces specific seed values into SYMCRYPTO's DPA countermeasure logic via the PSA crypto library interface, reducing entropy that normally masks power-trace leakage.

Side-channel key extraction

Attacker performs differential power analysis while the weakened engine processes AES/hashing operations, statistically recovering the loaded cryptographic key.

Impact: key compromise

Extracted keys enable decryption of protected data, firmware forgery, or device impersonation downstream of the compromised secure element.

How severe is it?

CVSS 3.1

N/A

EPSS

0.1%

chance of exploitation in 30 days

Higher than 1% of all CVEs

Source: EPSS v3 — FIRST.org

Exploitation Status

Exploit Available

Exploitation: MEDIUM

Sophistication

Advanced

Exploitation Confidence

medium

○ Public PoC indexed (trickest/cve)

Composite signal derived from CISA KEV, VulnCheck KEV, CISA SSVC, EPSS, Metasploit, Exploit-DB, trickest/cve, Nuclei templates, and inthewild.io exploitation reports.

What should I do?

1 step

1) Confirm with your hardware/embedded team whether any deployed device uses the Silicon Labs SiXG301 chip and SYMCRYPTO engine. 2) If so, consult and apply the vendor advisory at community.silabs.com/068Vm00000sjHs3 for firmware/microcode updates addressing the DPA seed-value weakness. 3) Since exploitation requires code execution, prioritize preventing that precondition: harden the device's software attack surface (secure boot, signed firmware, minimal debug interfaces) rather than treating this as a standalone patchable bug. 4) For any device using this chip to protect sensitive keys (including AI model or license-protection keys, if applicable), evaluate physical access controls, since DPA attacks require proximity/measurement access to the device. 5) No detection signature is feasible for a hardware side-channel weakness; track via vendor firmware version inventory instead.

What does CISA's SSVC say?

Decision Track

Exploitation none

Automatable No

Technical Impact partial

Source: CISA Vulnrichment (SSVC v2.0). Decision based on the CISA Coordinator decision tree.

How is it classified?

Code Execution Data Extraction Inference

Which compliance frameworks are affected?

Compliance analysis pending. Sign in for full compliance mapping when available.

Frequently Asked Questions

What is CVE-2026-4930?

This CVE describes a hardware-level flaw in SYMCRYPTO, the crypto acceleration engine on Silicon Labs' SiXG301 chip, where an attacker who already has code execution on the device can force weak seed values into the engine's differential power analysis (DPA) countermeasures, reducing their entropy and making loaded cryptographic keys easier to extract via power-analysis side channels. Despite the platform's "ml_library" tag in this feed, nothing in the advisory ties this to any AI/ML framework, model, or pipeline — it is a silicon/firmware secure-element issue on an IoT-class chip, and the classification appears to be a categorization artifact rather than a genuine AI attack surface. Exploitability is low on paper (EPSS 0.00101, effectively near the bottom of the scoring range despite the percentile label, no public exploit, no KEV listing, CISA SSVC decision is TRACK) and the attack requires an attacker to already have code execution — this is a post-compromise key-extraction technique, not an initial-access vector. For most security teams this warrants no urgent action beyond standard vendor patch tracking; the only reason to care is if your fleet uses SiXG301-based devices (e.g., embedded/IoT gateways) for key storage or secure boot, in which case you should check Silicon Labs' advisory (community.silabs.com/068Vm00000sjHs3) for firmware updates and treat it as a defense-in-depth/supply-chain hardware issue rather than an AI security incident.

Is CVE-2026-4930 actively exploited?

Proof-of-concept exploit code is publicly available for CVE-2026-4930, increasing the risk of exploitation.

How to fix CVE-2026-4930?

1) Confirm with your hardware/embedded team whether any deployed device uses the Silicon Labs SiXG301 chip and SYMCRYPTO engine. 2) If so, consult and apply the vendor advisory at community.silabs.com/068Vm00000sjHs3 for firmware/microcode updates addressing the DPA seed-value weakness. 3) Since exploitation requires code execution, prioritize preventing that precondition: harden the device's software attack surface (secure boot, signed firmware, minimal debug interfaces) rather than treating this as a standalone patchable bug. 4) For any device using this chip to protect sensitive keys (including AI model or license-protection keys, if applicable), evaluate physical access controls, since DPA attacks require proximity/measurement access to the device. 5) No detection signature is feasible for a hardware side-channel weakness; track via vendor firmware version inventory instead.

What systems are affected by CVE-2026-4930?

This vulnerability affects the following AI/ML architecture patterns: edge/embedded hardware security modules (unconfirmed AI relevance).

What is the CVSS score for CVE-2026-4930?

No CVSS score has been assigned yet.

What is the AI security impact?

Affected AI Architectures

edge/embedded hardware security modules (unconfirmed AI relevance)

What are the technical details?

Original Advisory

SYMCRYPTO is the SiXG301's host side hardware engine accessed by PSA crypto library that accelerates symmetric cryptographic operations (AES encryption/decryption and hashing). DPA Countermeasures on SYMCRYPTO can be weakened (reduced entropy) by forcing certain seed values if an attacker gains code execution capability on the impacted device. * Therefore, the keys loaded on SYMCRYPTO may be more vulnerable to extraction through DPA attacks than intended

Exploitation Scenario

An attacker first gains code execution on a device containing the SiXG301 chip (e.g., via a separate software vulnerability, physical access, or supply-chain compromise). Using that foothold, they invoke the PSA crypto library / SYMCRYPTO interface to force specific seed values into the engine's DPA countermeasure logic, reducing the randomization entropy that normally masks power consumption during cryptographic operations. The attacker then performs differential power analysis while the device processes AES or hashing operations with the weakened countermeasures active, statistically correlating power traces to recover bits of the cryptographic key loaded on the engine. With the extracted key, the attacker can decrypt protected data, forge signed firmware, or impersonate the device in downstream trust relationships — a meaningfully worse outcome than their original code-execution foothold alone.

Weaknesses (CWE)

CWE-331 Insufficient Entropy CWE-331 Insufficient Entropy

CWE-331 — Insufficient Entropy: The product uses an algorithm or scheme that produces insufficient entropy, leaving patterns or clusters of values that are more likely to occur than others.

[Implementation] Determine the necessary entropy to adequately provide for randomness and predictability. This can be achieved by increasing the number of bits of objects such as keys and seeds.

Source: MITRE CWE corpus.