CVE-2020-8929: Google Tink Java

Medium severity, CVSS 5.3. EPSS: 0.5% chance of exploitation in the next 30 days.

A mis-handling of invalid unicode characters in the Java implementation of Tink versions prior to 1.5 allows an attacker to change the ID part of a ciphertext, which result in the creation of a second ciphertext that can decrypt to the same plaintext. This can be a problem with encrypting deterministic AEAD with a single key, and rely on a unique ciphertext-per-plaintext.

Affected products

• Google Tink Java: before 1.5.0 (fixed in 1.5.0)

Published 2020-10-19. Last modified 2026-06-17.