CVE-2026-50185 — RustCrypto Cmov/CmovEq on aarch64 can produce wrong results if high-bits of registers are set
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. Fr…
Published: 2026-07-17 · CVSS: 2.0 · CVSS 4.0
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. From 0.1.1 until 0.5.4, the aarch64 implementations of Cmov and CmovEq in cmov/src/backends/aarch64.rs assume high bits are zero-extended when loading values smaller than a register, so set high bits such as [8..] in a Cmov selector or [16..] of self or other in the u16 and i16 CmovEq implementations can cause left.cmovz(&right, condition) to produce incorrect output. This issue is fixed in version 0.5.4.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7