PT-2026-31875 · Wolfcrypt · Wolfcrypt

Published 2026-04-10 · Updated 2026-04-10 · CVE-2026-5477

Positive Technologies (AI Summary)

CVSS v4.0

8.2

High

AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Name of the Vulnerable Software and Affected Versions wolfCrypt (affected versions not specified)

Description An integer overflow in the wolfCrypt CMAC implementation could allow for the forging of CMAC tags. The wc CmacUpdate function incorrectly skipped XOR-chaining on the first block due to a word32 wrap-around in the totalSz variable after approximately 4 GiB of block flushes. This allowed messages with a common suffix beyond the 4 GiB mark to produce identical CMAC tags, enabling a prefix-substitution forgery. The fix removes the guard condition, making the XOR operation unconditional.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Integer Overflow

Weakness Enumeration

CWE-190

Related Identifiers

CVE-2026-5477

Affected Products

Wolfcrypt

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-5477 · Security Note
• https://github.com/wolfSSL/wolfssl/pull/10102 · Note
• https://twitter.com/CVEnew/status/2042561752576217168 · Twitter Post