CVE-2026-115906: zip: AES Entry HMAC Authentication Bypass on Premature EOF

Vulnerability summary

CVE-2026-115906 is a medium (CVSS 6.5) vulnerability in zip-rs zip2.

Timeline

1. 26-10-2026
   PublishedVulnerability first disclosed.

Description

zip is a zip library for Rust that supports reading and writing simple ZIP files. From 0.6.0 until 9.0.0, the AES entry reader in src/aes.rs verifies its HMAC only when the attacker-controlled data counter reaches zero. If the underlying bounded reader reaches the real end of the archive while data_remaining is still positive, or if an encrypted entry has no payload, the reader can return a clean end of stream without reading and comparing the authentication tag. Applications using by_index_decrypt, by_name_decrypt, by_path_decrypt, or password-enabled by_index_with_options can therefore accept modified plaintext without an authentication error. This issue is fixed in version 9.0.0.

• CWE-354Improper Validation of Integrity Check ValueThe 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.
• CWE-1284Improper Validation of Specified Quantity in InputThe product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.