{"id":"CVE-2026-22698","state":"PUBLISHED","title":"RustCrypto SM2-PKE has 32-bit Biased Nonce Vulnerability","description":"RustCrypto: Elliptic Curves is general purpose Elliptic Curve Cryptography (ECC) support, including types and traits for representing various elliptic curve forms, scalars, points, and public/secret keys composed thereof. In versions 0.14.0-pre.0 and 0.14.0-rc.0, a  critical vulnerability exists in the SM2 Public Key Encryption (PKE) implementation where the ephemeral nonce k is generated with severely reduced entropy. A unit mismatch error causes the nonce generation function to request only 32 bits of randomness instead of the expected 256 bits. This reduces the security of the encryption from a 128-bit level to a trivial 16-bit level, allowing a practical attack to recover the nonce k and decrypt any ciphertext given only the public key and ciphertext. This issue has been patched via commit e4f7778.","publishedAt":"2026-01-10T05:17:19.993Z","updatedAt":"2026-01-12T16:48:30.706Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["RustCrypto elliptic-curves"],"affected":[{"vendor":"RustCrypto","product":"elliptic-curves","versions":[{"version":"= 0.14.0-pre.0","status":"affected"},{"version":"= 0.14.0-rc.0","status":"affected"}]}],"references":["https://github.com/RustCrypto/elliptic-curves/security/advisories/GHSA-w3g8-fp6j-wvqw","https://github.com/RustCrypto/elliptic-curves/pull/1600","https://github.com/RustCrypto/elliptic-curves/commit/4781762f23ff22ab34763410f648128055c93731","https://github.com/RustCrypto/elliptic-curves/commit/e4f77788130d065d760e57fb109370827110a525","https://crates.io/crates/sm2/0.14.0-pre.0","https://crates.io/crates/sm2/0.14.0-rc.0"],"weaknesses":["CWE-331"],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/22xxx/CVE-2026-22698.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-22698","state":"PUBLISHED","datePublished":"2026-01-10T05:17:19.993Z","dateUpdated":"2026-01-12T16:48:30.706Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-01-08T19:23:09.856Z"},"containers":{"cna":{"title":"RustCrypto SM2-PKE has 32-bit Biased Nonce Vulnerability","descriptions":[{"lang":"en","value":"RustCrypto: Elliptic Curves is general purpose Elliptic Curve Cryptography (ECC) support, including types and traits for representing various elliptic curve forms, scalars, points, and public/secret keys composed thereof. In versions 0.14.0-pre.0 and 0.14.0-rc.0, a  critical vulnerability exists in the SM2 Public Key Encryption (PKE) implementation where the ephemeral nonce k is generated with severely reduced entropy. A unit mismatch error causes the nonce generation function to request only 32 bits of randomness instead of the expected 256 bits. This reduces the security of the encryption from a 128-bit level to a trivial 16-bit level, allowing a practical attack to recover the nonce k and decrypt any ciphertext given only the public key and ciphertext. This issue has been patched via commit e4f7778."}],"affected":[{"vendor":"RustCrypto","product":"elliptic-curves","versions":[{"version":"= 0.14.0-pre.0","status":"affected"},{"version":"= 0.14.0-rc.0","status":"affected"}]}],"references":[{"url":"https://github.com/RustCrypto/elliptic-curves/security/advisories/GHSA-w3g8-fp6j-wvqw","name":"https://github.com/RustCrypto/elliptic-curves/security/advisories/GHSA-w3g8-fp6j-wvqw","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/RustCrypto/elliptic-curves/pull/1600","name":"https://github.com/RustCrypto/elliptic-curves/pull/1600","tags":["x_refsource_MISC"]},{"url":"https://github.com/RustCrypto/elliptic-curves/commit/4781762f23ff22ab34763410f648128055c93731","name":"https://github.com/RustCrypto/elliptic-curves/commit/4781762f23ff22ab34763410f648128055c93731","tags":["x_refsource_MISC"]},{"url":"https://github.com/RustCrypto/elliptic-curves/commit/e4f77788130d065d760e57fb109370827110a525","name":"https://github.com/RustCrypto/elliptic-curves/commit/e4f77788130d065d760e57fb109370827110a525","tags":["x_refsource_MISC"]},{"url":"https://crates.io/crates/sm2/0.14.0-pre.0","name":"https://crates.io/crates/sm2/0.14.0-pre.0","tags":["x_refsource_MISC"]},{"url":"https://crates.io/crates/sm2/0.14.0-rc.0","name":"https://crates.io/crates/sm2/0.14.0-rc.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.7,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-331","lang":"en","description":"CWE-331: Insufficient Entropy","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-01-10T05:17:19.993Z"},"source":{"advisory":"GHSA-w3g8-fp6j-wvqw","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-01-12T16:47:49.756087Z","id":"CVE-2026-22698","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-01-12T16:48:30.706Z"}}]}}}