CVE-2026-57062
LowCVSS 2.9Exploitation Probability (EPSS)
Low risk2th percentile — higher than 2% of all known CVEs
Summary
Vulnerability in the CMS parser in gpgsm of GnuPG (up to version 2.5.20) mishandles the CMS format for AES-GCM encryption. The aes-ICVlen field should be 12 bytes but 4 bytes is also accepted, which may lead to errors in data integrity verification.
Risk Assessment
The organization may be exposed to attacks involving manipulation of AES-GCM encrypted data, as accepting an incorrect initialization vector (ICV) length weakens the message authentication mechanism.
Recommendation
Immediately update GnuPG to a version later than 2.5.20 that includes a fix for this issue. Until the update is applied, avoid using gpgsm to process CMS messages with AES-GCM encryption.
Original NVD description (English source)
CMS (Cryptographic Message Syntax) parsing in gpgsm in GnuPG through 2.5.20 mishandles the CMS format for AES-GCM because aes-ICVlen is supposed to be 12 bytes but 4 bytes is accepted. NOTE: this is related to CVE-2026-34182.