Issue summary: ChaCha20-Poly1305 and AES-OCB decryption with an empty ciphertext can report success without verifying the supplied authentication tag when the operation is finalized by calling the EVP_Cipher() function.
Impact summary: Applications calling EVP_Cipher() on an empty ciphertext and expecting the call to check the AEAD tag may accept forged messages.
CWE: CWE-354 (Improper Validation of Integrity Check Value)
Description: The EVP_Cipher() API call for AEAD ciphers behaves like a one shot encryption and decryption call. It also verifies the AEAD tag after the decryption operation. However for AES-OCB and ChaCha20-Poly1305 ciphers it skipped the AEAD tag verification when an empty ciphertext was passed to the function. The callers of this function might believe that a successful return indicates a valid AEAD tag for these ciphers, even when that has not truly been validated in this case.
FIPS impact: no The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this CVE as the affected algorithms are not FIPS approved and thus not implemented in the FIPS module.
CVSS Details
- CVSS 3.1 Base Score: 9.1
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade openssl | Aug 26, 2026 | Aug 25, 2026 |
| Debian | — | Upgrade openssl | Aug 26, 2026 | Aug 26, 2026 |
| Freebsd | — | Upgrade openssl36Upgrade opensslUpgrade openssl34Upgrade openssl35Upgrade openssl40Upgrade FreeBSD | Aug 26, 2026 | Aug 25, 2026 |
| Http Openssl | — | Upgrade to the latest version of OpenSSL | Aug 27, 2026 | Aug 25, 2026 |
| Ubuntu | — | Upgrade libssl3Upgrade libssl3t64Upgrade openssl | Aug 26, 2026 | Aug 25, 2026 |
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