{"cve":"CVE-2026-54875","nvd":{"published":"2026-09-29T16:17:08.920","modified":"2026-10-08T01:19:29.883","status":"Analyzed","description":"Issue summary: A non-constant-time optimized implementation of scalar\npoint multiplication is used for SM2 private key operations on ARM64 and\nRISC-V platforms.\n\nImpact summary: An attacker able to measure the time taken by, or to observe\nthe cache-line access pattern of SM2 signing or decryption on an affected\nplatform can learn information about the secret scalar.\n\nCWE: CWE-208: Observable Timing Discrepancy\n\nDescription: On ARM64 and RISC-V processors, the SM2 curve uses an optimized\nscalar multiplication implementation whose conditional branches and table\nlook ups are chosen according to the bits of the secret scalar. The execution\ntime and the cache-access pattern therefore depend on the long-term private\nkey (during SM2 decryption) or the per-signature nonce (during SM2 signature\ngeneration), forming a timing and cache side-channel.\n\nFIPS Impact: no\nSM2 is not a FIPS algorithm and the optimized SM2 implementation is not part\nof the FIPS module.\n\nOpenSSL 4.0, 3.6, 3.5 and 3.4 are vulnerable to this issue on AArch64 and\nRISC-V.\n\nOpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue.\n\nOpenSSL 4.0 users should upgrade to OpenSSL 4.0.3.\nOpenSSL 3.6 users should upgrade to OpenSSL 3.6.5.\nOpenSSL 3.5 users should upgrade to OpenSSL 3.5.9.\nOpenSSL 3.4 users should upgrade to OpenSSL 3.4.8.\n\nThis issue was reported on 2 May 2026 by Abhinav Agarwal.\nIt was independently reported on 6 June 2026 by Feng Xue.\nThe fix was developed by Igor Ustinov.\n\n-- cut (non-publishing metadata for internal use) --\nReported by: Abhinav Agarwal, Feng Xue\nFixed by: Igor Ustinov","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","score":3.7},"cwes":["CWE-208"],"references":["https://github.com/openssl/openssl/commit/3f01bbc28f7e08211fcdc797fd43816504f94257","https://github.com/openssl/openssl/commit/469f3e42629f4a0b5631796e20c66c92c138a3e8","https://github.com/openssl/openssl/commit/9794ed473764839275cb701b4850f3c24d929c28","https://github.com/openssl/openssl/commit/dddad955d5ff3e9507619cf4e0f13e9988e2197c","https://openssl-library.org/news/secadv/20260929.txt"],"products":["openssl:openssl"],"source":"nvd","synced_at":"2026-10-19T22:56:48.555445741+00:00"},"epss":{"cve":"CVE-2026-54875","score":0.00479,"percentile":0.41015,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}