Non-Constant-Time SM2 Scalar Multiplication on ARM64 and RISC-V (CVE-2026-54875) | HOL Guard CVE

Low · CVSS 3.7CVE-2026-54875

Non-Constant-Time SM2 Scalar Multiplication on ARM64 and RISC-V

Answer in brief

CVE-2026-54875 records a Low severity (CVSS 3.7) vulnerability in Non-Constant-Time SM2 Scalar Multiplication on ARM64 and RISC-V. The current sources do not mark it as known exploited. The current feed maps OpenSSL/OpenSSL (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 29, 2026Updated Sep 29, 2026Source checked Sep 29, 2026First seen by HOL Sep 29, 2026Material review Sep 29, 2026

Upstream Advisory

Key facts

Risk: Low · CVSS 3.7
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 3.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps OpenSSL/OpenSSL (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
OpenSSL/OpenSSLgeneric	>=4.0.0 <4.0.3 \|\| >=3.6.0 <3.6.5 \|\| >=3.5.0 <3.5.9 \|\| >=3.4.0 <3.4.8	4.0.3, 3.6.5, 3.5.9, 3.4.8

Recommended response

Check inventory. Check lockfiles and deployed manifests for OpenSSL/OpenSSL.
Review the reported fix. Update OpenSSL/OpenSSL to 4.0.3 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 29, 2026

Sources and claim methodology

Upstream source description

Issue summary: A non-constant-time optimized implementation of scalar point multiplication is used for SM2 private key operations on ARM64 and RISC-V platforms. Impact summary: An attacker able to measure the time taken by, or to observe the cache-line access pattern of SM2 signing or decryption on an affected platform can learn information about the secret scalar. CWE: CWE-208: Observable Timing Discrepancy Description: On ARM64 and RISC-V processors, the SM2 curve uses an optimized scalar multiplication implementation whose conditional branches and table look ups are chosen according to the bits of the secret scalar. The execution time and the cache-access pattern therefore depend on the long-term private key (during SM2 decryption) or the per-signature nonce (during SM2 signature generation), forming a timing and cache side-channel. FIPS Impact: no SM2 is not a FIPS algorithm and the optimized SM2 implementation is not part of the FIPS module. OpenSSL 4.0, 3.6, 3.5 and 3.4 are vulnerable to this issue on AArch64 and RISC-V. OpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue. OpenSSL 4.0 users should upgrade to OpenSSL 4.0.3. OpenSSL 3.6 users should upgrade to OpenSSL 3.6.5. OpenSSL 3.5 users should upgrade to OpenSSL 3.5.9. OpenSSL 3.4 users should upgrade to OpenSSL 3.4.8. This issue was reported on 2 May 2026 by Abhinav Agarwal. It was independently reported on 6 June 2026 by Feng Xue. The fix was developed by Igor Ustinov. -- cut (non-publishing metadata for internal use) -- Reported by: Abhinav Agarwal, Feng Xue Fixed by: Igor Ustinov

Quoted source text, attributed separately from HOL analysis.