Integer Overflow or Wraparound Affecting wolfssl/wolfssl package, versions [,5.9.1)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-UNMANAGED-WOLFSSLWOLFSSL-15990762
- published12 Apr 2026
- disclosed10 Apr 2026
- creditUnknown
Introduced: 10 Apr 2026
NewCVE-2026-5477 (opens in a new tab)How to fix?
Upgrade wolfssl/wolfssl to version 5.9.1 or higher.
Overview
Affected versions of this package are vulnerable to Integer Overflow or Wraparound due to an integer overflow in the wc_CmacUpdate function. An attacker can generate forged CMAC tags by exploiting the wraparound of the totalSz variable after processing 4 GiB of data, which causes the function to erroneously skip XOR-chaining and discard the live CBC-MAC chain state. This allows two messages with a common suffix beyond the 4 GiB mark to produce identical CMAC tags, enabling unauthorized message forgery.