{"schema":"threatline.record/2","record":{"id":"CVE-2026-55174","aliases":["GHSA-c7q2-gv3g-rgxm"],"summary":"UltrafastSecp256k1: ECDSA adaptor verification accepts non-adaptable pre-signatures due to missing DLEQ binding","details":"UltrafastSecp256k1 is a high-performance, multi-backend secp256k1 engine with reproducible audit evidence, compatibility shims, and profile-based review scopes. Prior to version 4.2.0, UltrafastSecp256k1's ECDSA adaptor pre-signature verification accepts forged adaptor pre-signatures whose \"r\" value is not cryptographically bound to the adaptor point \"T\". This issue has been patched in version 4.2.0.","categories":["Unclassified"],"product":"UltrafastSecp256k1","vendor":"shrec","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-55174","source_modified_at":"2026-09-30T19:52:01.569Z","fetched_at":"2026-10-23T18:52:38.922436Z","product":"UltrafastSecp256k1","vendor":"shrec","versions":[{"version":"< 4.2.0","status":"affected"}],"defaultStatus":null}],"fixed_versions":[],"cvss":5.9,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.0015,"percentile":0.0385,"score_date":"2026-10-23"},"published_at":"2026-09-30T15:49:10.453Z","modified_at":"2026-09-30T19:52:01.569Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-55174","fetched_at":"2026-10-23T18:52:38.922436Z","source_modified_at":"2026-09-30T19:52:01.569Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-55174","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/shrec/UltrafastSecp256k1/security/advisories/GHSA-c7q2-gv3g-rgxm","tags":["exploit"]},{"source":"CVE List","url":"https://github.com/shrec/UltrafastSecp256k1/commit/5478ef566c6af91b48a45c0c61f161f5b1071981","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/shrec/UltrafastSecp256k1/releases/tag/v4.2.0","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/shrec/UltrafastSecp256k1/releases/tag/v4.2.1","tags":["x_refsource_MISC"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"poc","automatable":"no","technical_impact":"partial","assessed_at":"2026-09-30T19:51:52.522461Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-09-30T19:52:01.569Z","content_hash":"1e4a2aa2931edbff9d8c766f50a4fdb38df697cd88440b22400a266e809733d1"}}