CVE-2026-23519

HIGH8.9

RustCrypto cmov: thumbv6m-none-eabi compiler emits non-constant time assembly when using cmovnz

Published Jan 15, 2026

Modified 1 months ago

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.

References

WEB

https://github.com/RustCrypto/utils/commit/55977257e7c82a309d5e8abfdd380a774f0f9778

DETECTION

https://github.com/RustCrypto/utils/security/advisories/GHSA-2gqc-6j2q-83qp

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2026-23519

CVSS Analysis

CVSS v4.0

8.9

Exploitability

Attack Vector