{"api_version":"1","generated_at":"2026-10-02T21:36:48+00:00","cve":"CVE-2026-54872","urls":{"html":"https://cve.report/CVE-2026-54872","api":"https://cve.report/api/cve/CVE-2026-54872.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-54872","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-54872"},"summary":{"title":"Timing Side-Channel in Scalar Multiplication for Non-NIST EC Curves","description":"Issue summary: The generic elliptic-curve scalar multiplication used for\nECDSA and SM2 signature operations with curves that do not have a dedicated\nimplementation leaks information about the secret nonce through timing.\n\nImpact summary: An attacker able to measure 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: The generic elliptic-curve scalar multiplication used for\ncurves that do not have a dedicated constant-time implementation pads the\nsecret scalar with non-constant-time BIGNUM operations, so the time taken\ndepends on the value of the secret scalar derived from the ECDSA and SM2 nonce.\n\nThe leak is very small; observing it requires a large number of\nmeasurements. The effect is largest for curves whose group order lies\non a machine-word boundary, such as brainpoolP384r1.\n\nApplications using ECDSA signing over the Brainpool and other generic prime\ncurves, and SM2 signing on platforms that use the generic implementation,\nare vulnerable to this issue.\n\nThe NIST curves P-256, P-384 and P-521 use dedicated constant-time\nimplementations and are not affected.\n\nFIPS Impact: no\nThe FIPS modules are not affected: the approved NIST curves used in the FIPS\nprovider have dedicated constant-time implementations and do not use the\naffected code path.","state":"PUBLISHED","assigner":"openssl","published_at":"2026-09-29 16:17:08","updated_at":"2026-09-29 21:27:41"},"problem_types":["CWE-208","CWE-208 CWE-208 Observable Timing Discrepancy"],"metrics":[{"version":"3.1","source":"ADP","type":"DECLARED","score":"3.7","severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","data":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":3.7,"baseSeverity":"LOW","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","version":"3.1"}},{"version":"3.1","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary","score":"3.7","severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","data":{"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"}}],"references":[{"url":"https://github.com/openssl/openssl/commit/3f7e1363dccec6f7732bb9e9fa471bb6e4aa68cb","name":"https://github.com/openssl/openssl/commit/3f7e1363dccec6f7732bb9e9fa471bb6e4aa68cb","refsource":"openssl-security@openssl.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/openssl/openssl/commit/7d83bc7764999dfd91b83b4f0815b45390422afd","name":"https://github.com/openssl/openssl/commit/7d83bc7764999dfd91b83b4f0815b45390422afd","refsource":"openssl-security@openssl.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/openssl/openssl/commit/1a5bee8dc57430a2be69cd1ffe7fec6a62f4f179","name":"https://github.com/openssl/openssl/commit/1a5bee8dc57430a2be69cd1ffe7fec6a62f4f179","refsource":"openssl-security@openssl.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://openssl-library.org/news/secadv/20260929.txt","name":"https://openssl-library.org/news/secadv/20260929.txt","refsource":"openssl-security@openssl.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/openssl/openssl/commit/8166827a78aad164a07aa86dea2b425403ced471","name":"https://github.com/openssl/openssl/commit/8166827a78aad164a07aa86dea2b425403ced471","refsource":"openssl-security@openssl.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-54872","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54872","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"OpenSSL","product":"OpenSSL","version":"affected 4.0.0 4.0.3 semver","platforms":[]},{"source":"CNA","vendor":"OpenSSL","product":"OpenSSL","version":"affected 3.6.0 3.6.5 semver","platforms":[]},{"source":"CNA","vendor":"OpenSSL","product":"OpenSSL","version":"affected 3.5.0 3.5.9 semver","platforms":[]},{"source":"CNA","vendor":"OpenSSL","product":"OpenSSL","version":"affected 3.4.0 3.4.8 semver","platforms":[]},{"source":"CNA","vendor":"OpenSSL","product":"OpenSSL","version":"affected 3.0.0 3.0.23 semver","platforms":[]},{"source":"CNA","vendor":"OpenSSL","product":"OpenSSL","version":"affected 1.1.1 1.1.1zj custom","platforms":[]},{"source":"CNA","vendor":"OpenSSL","product":"OpenSSL","version":"affected 1.0.2 1.0.2zs 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developer","value":"Igor Ustinov"}],"datePublic":"2026-09-29T14:21:57.000Z","descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"Issue summary: The generic elliptic-curve scalar multiplication used for<br>ECDSA and SM2 signature operations with curves that do not have a dedicated<br>implementation leaks information about the secret nonce through timing.<br><br>Impact summary: An attacker able to measure signing times may learn<br>information about the per-signature secret nonce, which over many signatures<br>can, via a lattice / Hidden Number Problem attack, lead to recovery of the<br>private key.<br><br>CWE: CWE-208: Observable Timing Discrepancy<br><br>Description: The generic elliptic-curve scalar multiplication used for<br>curves that do not have a dedicated constant-time implementation pads the<br>secret scalar with non-constant-time BIGNUM operations, so the time taken<br>depends on the value of the secret scalar derived from the ECDSA and SM2 nonce.<br><br>The leak is very small; observing it requires a large number of<br>measurements. The effect is largest for curves whose group order lies<br>on a machine-word boundary, such as brainpoolP384r1.<br><br>Applications using ECDSA signing over the Brainpool and other generic prime<br>curves, and SM2 signing on platforms that use the generic implementation,<br>are vulnerable to this issue.<br><br>The NIST curves P-256, P-384 and P-521 use dedicated constant-time<br>implementations and are not affected.<br><br>FIPS Impact: no<br>The FIPS modules are not affected: the approved NIST curves used in the FIPS<br>provider have dedicated constant-time implementations and do not use the<br>affected code path."}],"value":"Issue summary: The generic elliptic-curve scalar multiplication used for\nECDSA and SM2 signature operations with curves that do not have a dedicated\nimplementation leaks information about the secret nonce through timing.\n\nImpact summary: An attacker able to measure 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: The generic elliptic-curve scalar multiplication used for\ncurves that do not have a dedicated constant-time implementation pads the\nsecret scalar with non-constant-time BIGNUM operations, so the time taken\ndepends on the value of the secret scalar derived from the ECDSA and SM2 nonce.\n\nThe leak is very small; observing it requires a large number of\nmeasurements. The effect is largest for curves whose group order lies\non a machine-word boundary, such as brainpoolP384r1.\n\nApplications using ECDSA signing over the Brainpool and other generic prime\ncurves, and SM2 signing on platforms that use the generic implementation,\nare vulnerable to this issue.\n\nThe NIST curves P-256, P-384 and P-521 use dedicated constant-time\nimplementations and are not affected.\n\nFIPS Impact: no\nThe FIPS modules are not affected: the approved NIST curves used in the FIPS\nprovider have dedicated constant-time implementations and do not use the\naffected code path."}],"metrics":[{"format":"other","other":{"content":{"text":"Low"},"type":"https://openssl-library.org/policies/general/security-policy/"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-208","description":"CWE-208 Observable Timing Discrepancy","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-09-29T15:32:15.075Z","orgId":"3a12439a-ef3a-4c79-92e6-6081a721f1e5","shortName":"openssl"},"references":[{"name":"OpenSSL Advisory","tags":["vendor-advisory"],"url":"https://openssl-library.org/news/secadv/20260929.txt"},{"name":"4.0.3 git commit","tags":["patch"],"url":"https://github.com/openssl/openssl/commit/8166827a78aad164a07aa86dea2b425403ced471"},{"name":"3.6.5 git commit","tags":["patch"],"url":"https://github.com/openssl/openssl/commit/1a5bee8dc57430a2be69cd1ffe7fec6a62f4f179"},{"name":"3.5.9 git commit","tags":["patch"],"url":"https://github.com/openssl/openssl/commit/3f7e1363dccec6f7732bb9e9fa471bb6e4aa68cb"},{"name":"3.4.8 git commit","tags":["patch"],"url":"https://github.com/openssl/openssl/commit/7d83bc7764999dfd91b83b4f0815b45390422afd"}],"source":{"discovery":"UNKNOWN"},"title":"Timing Side-Channel in Scalar Multiplication for Non-NIST EC Curves","x_generator":{"engine":"Vulnogram 0.2.0"}}},"cveMetadata":{"assignerOrgId":"3a12439a-ef3a-4c79-92e6-6081a721f1e5","assignerShortName":"openssl","cveId":"CVE-2026-54872","datePublished":"2026-09-29T15:32:15.075Z","dateReserved":"2026-06-16T10:18:08.635Z","dateUpdated":"2026-09-29T17:28:12.657Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-29 16:17:08","lastModifiedDate":"2026-09-29 21:27:41","problem_types":["CWE-208","CWE-208 CWE-208 Observable Timing Discrepancy"],"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":"2026-09-29T17:27:46.959054Z","id":"CVE-2026-54872","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"54872","Ordinal":"1","Title":"Timing Side-Channel in Scalar Multiplication for Non-NIST EC Cur","CVE":"CVE-2026-54872","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"54872","Ordinal":"1","NoteData":"Issue summary: The generic elliptic-curve scalar multiplication used for\nECDSA and SM2 signature operations with curves that do not have a dedicated\nimplementation leaks information about the secret nonce through timing.\n\nImpact summary: An attacker able to measure 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: The generic elliptic-curve scalar multiplication used for\ncurves that do not have a dedicated constant-time implementation pads the\nsecret scalar with non-constant-time BIGNUM operations, so the time taken\ndepends on the value of the secret scalar derived from the ECDSA and SM2 nonce.\n\nThe leak is very small; observing it requires a large number of\nmeasurements. The effect is largest for curves whose group order lies\non a machine-word boundary, such as brainpoolP384r1.\n\nApplications using ECDSA signing over the Brainpool and other generic prime\ncurves, and SM2 signing on platforms that use the generic implementation,\nare vulnerable to this issue.\n\nThe NIST curves P-256, P-384 and P-521 use dedicated constant-time\nimplementations and are not affected.\n\nFIPS Impact: no\nThe FIPS modules are not affected: the approved NIST curves used in the FIPS\nprovider have dedicated constant-time implementations and do not use the\naffected code path.","Type":"Description","Title":"Timing Side-Channel in Scalar Multiplication for Non-NIST EC Cur"}]}}}