CVE-2026-55967 AES-GCM streaming APIs do not reject >64 GiB cumulative single messages, enabling counter wrap and keystream reuse
Attackers can recover plaintext by exploiting counter wrap in AES-GCM streaming APIs when processing messages larger than 64 GiB.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-55967?
CVE-2026-55967 is a low-severity vulnerability in Wolfssl Wolfssl, published on 25 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
AES-GCM encryption/decryption with extremely large cumulative single message sizes (>64 GiB) were not properly rejected by the streaming APIs, allowing counter wrap, keystream reuse, and consequent plaintext recovery.
Weakness: CWE-323
Which versions are affected by CVE-2026-55967?
It affects 1 product.
Products include Wolfssl Wolfssl.
How do I fix CVE-2026-55967?
Apply the vendor's patch.
Is CVE-2026-55967 being exploited?
There is no known exploitation of CVE-2026-55967 in the wild and no public exploit code.
Other vulnerabilities in Wolfssl Wolfssl
Sources
Also known as DEBIAN-CVE-2026-55967, GHSA-q4q5-jx42-4xp9, JLSEC-2026-739, UBUNTU-CVE-2026-55967.