{"attribution":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","cve":{"id":"CVE-2026-77696","sourceIdentifier":"openssl-security@openssl.org","published":"2026-09-29T16:17:11.493","lastModified":"2026-11-10T13:19:40.053","vulnStatus":"Modified","cveTags":[],"descriptions":[{"lang":"en","value":"Issue summary: SM2 signature generation uses non-constant-time arithmetic\non secret values, forming a timing side-channel.\n\nImpact summary: An attacker able to measure SM2 signing times may learn\ninformation about the per-signature secret nonce, which over many signatures\ncan, via a lattice / Hidden Number Problem attack, lead to recovery of the\nprivate key.\n\nCWE: CWE-208: Observable Timing Discrepancy\n\nDescription: SM2 signature generation computes the signature value using\nvariable-time BIGNUM operations on the secret nonce and the private key, so\nthe time taken to produce an SM2 signature depends on these secret values,\nforming a timing side-channel.\n\nApplications performing SM2 signature generation are affected on all\nplatforms.\n\nFIPS Impact: no\nSM2 is not a FIPS algorithm."}],"affected":[{"source":"openssl-security@openssl.org","affectedData":[{"vendor":"OpenSSL","product":"OpenSSL","defaultStatus":"unaffected","versions":[{"version":"4.0.0","lessThan":"4.0.3","versionType":"semver","status":"affected"},{"version":"3.6.0","lessThan":"3.6.5","versionType":"semver","status":"affected"},{"version":"3.5.0","lessThan":"3.5.9","versionType":"semver","status":"affected"},{"version":"3.4.0","lessThan":"3.4.8","versionType":"semver","status":"affected"},{"version":"3.0.0","lessThan":"3.0.23","versionType":"semver","status":"affected"},{"version":"1.1.1","lessThan":"1.1.1zj","versionType":"custom","status":"affected"}]}]},{"source":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","affectedData":[{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)","defaultStatus":"unknown","versions":[{"version":"V3.1.7","lessThan":"*","versionType":"custom","status":"affected"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)","defaultStatus":"unknown","versions":[{"version":"V3.1.7","lessThan":"*","versionType":"custom","status":"affected"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)","defaultStatus":"unknown","versions":[{"version":"V3.1.7","lessThan":"*","versionType":"custom","status":"affected"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)","defaultStatus":"unknown","versions":[{"version":"V3.1.7","lessThan":"*","versionType":"custom","status":"affected"}]},{"vendor":"Siemens","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)","defaultStatus":"unknown","versions":[{"version":"V3.1.7","lessThan":"*","versionType":"custom","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","baseScore":3.7,"baseSeverity":"LOW","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"NONE"},"exploitabilityScore":2.2,"impactScore":1.4}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-29T16:51:30.070097Z","id":"CVE-2026-77696","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"openssl-security@openssl.org","type":"Secondary","description":[{"lang":"en","value":"CWE-208"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*","versionStartIncluding":"1.1.1","versionEndExcluding":"1.1.1zj","matchCriteriaId":"AB24C69B-F66B-4BC6-99E8-4D3088607B00"},{"vulnerable":true,"criteria":"cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0.0","versionEndExcluding":"3.0.23","matchCriteriaId":"C9AFA409-BE77-40FB-8191-3405AC8F52C0"},{"vulnerable":true,"criteria":"cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4.0","versionEndExcluding":"3.4.8","matchCriteriaId":"707E1EC7-0538-4F9F-96CB-C89FECC1F3ED"},{"vulnerable":true,"criteria":"cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*","versionStartIncluding":"3.5.0","versionEndExcluding":"3.5.9","matchCriteriaId":"B822E02B-8728-4C34-98BC-52D0A0A735B3"},{"vulnerable":true,"criteria":"cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*","versionStartIncluding":"3.6.0","versionEndExcluding":"3.6.5","matchCriteriaId":"96C892B6-618B-4CB9-85B6-76C641D17532"},{"vulnerable":true,"criteria":"cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0.0","versionEndExcluding":"4.0.3","matchCriteriaId":"BC4A99CC-483D-4C81-A95F-6AEB2BF1B500"}]}]}],"references":[{"url":"https://github.com/openssl/openssl/commit/1c4aed808a7aea32d2d013049c2e0d9fef164fc9","source":"openssl-security@openssl.org","tags":["Patch"]},{"url":"https://github.com/openssl/openssl/commit/20b20628d39b2dcc4677194bd68c7c060fa598cb","source":"openssl-security@openssl.org","tags":["Patch"]},{"url":"https://github.com/openssl/openssl/commit/419f5cb519721dceed393dbc524d79e487c72e64","source":"openssl-security@openssl.org","tags":["Patch"]},{"url":"https://github.com/openssl/openssl/commit/6b90445a56b99a328ac1feba058abf976504f440","source":"openssl-security@openssl.org","tags":["Patch"]},{"url":"https://openssl-library.org/news/secadv/20260929.txt","source":"openssl-security@openssl.org","tags":["Vendor Advisory"]},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html","source":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}]}}