CVE-2026-50185CWE-758

CVE-2026-50185

Low · published July 17, 2026

CVSS v3.1
3.3
EPSS
0%
Percentile
5.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
3.3 · LOW
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00157 · 5.2th percentile
Weakness
CWE-758 · Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
Published
2026-07-17T23:17Z
Affected products (1)
ProductVersionsFixed in
rustcrypto/cmov≥ 0.1.1, < 0.5.40.5.4
References (4)
EPSS history
Timeline
  • 17 JUL 18:35Z
    RustCrypto Cmov/CmovEq on aarch64 can produce wrong results if high-bits of registers are set
    cvelistv5