CVE-2026-10512 — X25519 x86_64 assembly final reduction leaves non-canonical field element

Description (CNA)

The X25519 x86_64 assembly implementation fails to clear the most significant bit during the final modular reduction, so the computed result may not be fully reduced modulo the field prime 2^255 - 19. This can leave the field element in a non-canonical form, producing an incorrect result from the scalar multiplication and potentially a wrong shared secret. The final carry-propagation chains in the x64 and AVX2 reduction routines could overflow into the top bit, and the high limb was not masked afterward, so the 255-bit field element was left non-canonical.

Affected (CNA)

Vendor / product	Versions
wolfSSL / wolfSSL	affected 5.6.4 through 5.9.1

CWE

CWE-682

References

https://github.com/wolfSSL/wolfssl/pull/10536
https://www.wolfssl.com/docs/security-vulnerabilities/

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.