OpenSSL CVE-2026-54875

Exploitation requires that the target use the SM2 elliptic-curve algorithm (Chinese national cryptography, uncommon outside PRC-facing deployments) AND run on an ARM64 or RISC-V platform where the non-constant-time scalar-multiplication code path is compiled in. The attacker must be able to observe and precisely measure the timing of many SM2 operations and perform statistical side-channel analysis to recover key material; a single interaction is insufficient. These factors - specific algorithm, specific CPU architectures, and the high measurement volume/precision reflected in AC:H - sharply limit realistic exploitation despite the network attack vector and lack of authentication (PR:N).

This is a genuinely low-priority issue despite being bundled into a High-severity OpenSSL release - the 'High' label applies to a sibling CVE (the DTLS stale-buffer OOB read, CVE-2026-84782), NOT to CVE-2026-54875. The provided CVSS 3.1 score is 3.7 (Low) with vector AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N, and CWE-208 (Observable Timing Discrepancy) correctly frames it: non-constant-time SM2 scalar multiplication on ARM64 and RISC-V builds could leak secret-dependent timing that, over many precise measurements, might reveal private key bits. AC:H is well-justified - exploitation demands statistical timing analysis over a large sample under favorable conditions, not a single request. No EPSS score, KEV entry, or public exploit was provided, so exploitation status is: no public exploit identified at time of analysis. The scope is further narrowed by requiring the SM2 algorithm (a Chinese national curve rarely used outside PRC-facing deployments) AND specific ARM64/RISC-V targets. There are no conflicting signals here: every signal (Low CVSS, high complexity, narrow algorithm/platform gating, side-channel class) points the same direction - real but marginal risk. The confidentiality-only, partial (C:L) impact and absence of exploitation evidence make this a patch-in-routine-cycle item, not an emergency.

An attacker able to obtain precise, repeated timing measurements of SM2 signing or key-agreement operations on a victim running OpenSSL on ARM64 or RISC-V collects thousands of samples and applies statistical side-channel analysis to recover secret-dependent scalar-multiplication timing. Over time this may leak portions of the SM2 private key. No public exploit code was identified, and the CVSS AC:H reflects the substantial measurement precision and volume required.