Improper validation of integrity check value in OpenSSL - CVE-2026-75803
Published: August 26, 2026
Vulnerability identifier: #VU145424
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-75803
CWE-ID: CWE-354
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to bypass integrity checks.
The vulnerability exists due to improper validation of integrity check value in EVP_Cipher() for ChaCha20-Poly1305 and AES-OCB when decrypting an empty ciphertext. A local user can provide a forged empty-ciphertext message with a supplied authentication tag to bypass integrity checks.
The issue occurs when applications use EVP_Cipher() and expect a successful return value to indicate that the AEAD tag was verified.
Affected software
OpenSSL
Debian Linux
openssl (Debian package)
Debian Linux
openssl (Debian package)
How to mitigate CVE-2026-75803
Install security update from vendor's website.
OpenSSL - addressed in versions 3.0.22, 3.4.7, 3.5.8, 3.6.4, 4.0.2
openssl (Debian package) - update to 3.5.7-1~deb13u2
openssl (Debian package) - update to 3.5.7-1~deb13u2