{"id":"CVE-2026-23519","aliases":["GHSA-2gqc-6j2q-83qp","RUSTSEC-2026-0003"],"url":"https://o3.security/vulnerability/CVE-2026-23519","summary":"RustCrypto cmov: thumbv6m-none-eabi compiler emits non-constant time assembly when using cmovnz","details":"RustCrypto CMOV provides conditional move CPU intrinsics which are guaranteed on major platforms to execute in constant-time and not be rewritten as branches by the compiler. Prior to 0.4.4, the thumbv6m-none-eabi (Cortex M0, M0+ and M1) compiler emits non-constant time assembly when using cmovnz (portable version). This vulnerability is fixed in 0.4.4.","published":"2026-01-15T19:13:54.440Z","modified":"2026-08-12T03:51:11.803350455Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"cmov","fixedVersion":"0.4.4"}],"fix":{"url":"https://github.com/RustCrypto/utils/commit/55977257e7c82a309d5e8abfdd380a774f0f9778","label":"RustCrypto/utils@5597725"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23519.json"},{"type":"ADVISORY","url":"https://github.com/RustCrypto/utils/security/advisories/GHSA-2gqc-6j2q-83qp"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23519"},{"type":"FIX","url":"https://github.com/RustCrypto/utils/commit/55977257e7c82a309d5e8abfdd380a774f0f9778"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:11.803350455Z"}}