CVE-2026-104254

Name of the Vulnerable Software and Affected Versions liboqs versions 0.11.0 through 0.16.0

Description Builds configured with OQS ENABLE SIG STFL LMS=ON can read beyond a caller-supplied signature buffer when an untrusted truncated LMS or HSS-LMS signature reaches the OQS SIG STFL verify() or OQS SIG STFL alg lms verify() functions. In the hss validate signature init() function within src/sig stfl/lms/external/hss verify inc.c, consumed-length checks fail to ensure that the bottom-level q and C fields remain available, potentially allowing a read of up to 32 bytes past the buffer. Additionally, in version 0.16.0, the is hss public key() function reads at offset 8 after only a four-byte length check, allowing an over-read of up to eight bytes. This can lead to a verifier crash and denial of service, although the read data is consumed by an internal hash and not exposed.

Recommendations Update to version 0.17.0. As a temporary workaround, disable the OQS ENABLE SIG STFL LMS configuration option.