VULNERABILITY INTELLIGENCE

CVE-2018-10903

CVSS score7.5 HIGH
EPSS probability3.20%
CISA KEVNot currently listed
Published2018-07-30
Last modified2026-06-17
CVSS vectorCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Description

A flaw was found in python-cryptography versions between >=1.9.0 and <2.3. The finalize_with_tag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalize_with_tag an attacker could craft an invalid payload with a shortened tag (e.g. 1 byte) such that they would have a 1 in 256 chance of passing the MAC check. GCM tag forgeries can cause key leakage.

Weakness classification

  • CWE-20: Improper Input Validation

Primary references