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.

• azl3 gnupg2 2.4.9-2 on Azure Linux 3.0

• azl3 gnupg2 2.4.9-3 on Azure Linux 3.0

SecurityAlert records field-level changes from the point we begin following a bulletin. Earlier vendor changes may not have a field-by-field record.

1. Oct 22, 2026 at 7:40 AM UTC
   • The vendor changed the advisory's last-updated date.

1. Jun 27, 2026 at 1:05 AM UTC
   Published by Microsoft Security Response Center

   The publication date reported by the vendor.

2. Sep 28, 2026 at 11:20 AM UTC
   Added to SecurityAlert

   We collected the advisory from the official source.

3. Oct 22, 2026 at 1:12 AM UTC
   Updated by Microsoft Security Response Center

   The vendor changed the advisory after it was first published.

4. Nov 11, 2026 at 2:20 AM UTC
   Confirmed at the source

   Our collector saw this advisory during a later source check.