CVE-2026-5479
Received Received - Intake
Authentication Bypass in wolfSSL EVP ChaCha20-Poly1305 Decryption

Publication date: 2026-04-10

Last updated on: 2026-04-29

Assigner: wolfSSL Inc.

Description
In wolfSSL's EVP layer, the ChaCha20-Poly1305 AEAD decryption path in wolfSSL_EVP_CipherFinal (and related EVP cipher finalization functions) fails to verify the authentication tag before returning plaintext to the caller. When an application uses the EVP API to perform ChaCha20-Poly1305 decryption, the implementation computes or accepts the tag but does not compare it against the expected value.
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Meta Information
Published
2026-04-10
Last Modified
2026-04-29
Generated
2026-06-16
AI Q&A
2026-04-10
EPSS Evaluated
2026-06-15
NVD
CVE-2026-5479
EUVD
EUVD-2026-21292
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
wolfssl wolfssl to 5.9.1 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-354 The product does not validate or incorrectly validates the integrity check values or "checksums" of a message. This may prevent it from detecting if the data has been modified or corrupted in transmission.
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Executive Summary

This vulnerability exists in wolfSSL's EVP layer, specifically in the ChaCha20-Poly1305 AEAD decryption path within the function wolfSSL_EVP_CipherFinal and related EVP cipher finalization functions.

The issue is that the decryption process fails to verify the authentication tag before returning the plaintext to the caller. Although the implementation computes or accepts the tag, it does not compare it against the expected value, which means the integrity and authenticity of the decrypted data are not properly checked.

Impact Analysis

Because the authentication tag is not verified during decryption, an attacker could potentially manipulate ciphertext without detection, leading to the acceptance of tampered or forged data as valid plaintext.

This undermines the security guarantees of the ChaCha20-Poly1305 AEAD encryption scheme, potentially allowing unauthorized data modification or injection, which can compromise data integrity and confidentiality.

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