CVE-2026-50185
RustCrypto Cmov/CmovEq on aarch64 can produce wrong results if high-bits of registers are set
- State
- Published
- Severity
- 2.0 Low
- Published
- Jul 17, 2026
- Updated
- Jul 20, 2026
- Reserved
- Jun 3, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 2.0 Low | CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N | GitHub_M |
Weaknesses
- CWE-758 Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
Affected Products
| Product | Versions |
|---|---|
utilsRustCrypto |
|
References
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