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.
History

Fri, 23 Jan 2026 19:00:00 +0000

Type Values Removed Values Added
First Time appeared Rustcrypto cmov
Weaknesses CWE-203
CPEs cpe:2.3:a:rustcrypto:cmov:*:*:*:*:*:rust:*:*
Vendors & Products Rustcrypto cmov
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Fri, 16 Jan 2026 14:15:00 +0000

Type Values Removed Values Added
First Time appeared Rustcrypto
Rustcrypto utils
Vendors & Products Rustcrypto
Rustcrypto utils

Thu, 15 Jan 2026 20:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 15 Jan 2026 19:30:00 +0000

Type Values Removed Values Added
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. 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.
Title RustCrypto cmov: thumbv6m-none-eabi compiler emits non-constant time assembly when using cmovnz
Weaknesses CWE-208
References
Metrics cvssV4_0

{'score': 8.9, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-01-15T19:13:54.440Z

Updated: 2026-01-15T19:57:48.741Z

Reserved: 2026-01-13T18:22:43.980Z

Link: CVE-2026-23519

cve-icon Vulnrichment

Updated: 2026-01-15T19:57:33.242Z

cve-icon NVD

Status : Analyzed

Published: 2026-01-15T20:16:05.313

Modified: 2026-01-23T18:59:58.223

Link: CVE-2026-23519

cve-icon Redhat

No data.