Vulnerability · Published Jun 25, 2026 · Assigned by wolfSSL
CVE-2026-55967AES-GCM streaming APIs do not reject >64 GiB cumulative single messages, enabling counter wrap and keystream reuse
Low 2.0
In plain English
A low-severity security flaw in wolfSSL from wolfSSL. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 4.0)2.0Low
Exploit odds (30 days)0.2%top 92.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.24 | wolfssl | 5.9.2-r0 | ALPINE-CVE-2026-55967 |
| Debian:12 | wolfssl | 5.5.4-2+deb12u3 | DEBIAN-CVE-2026-55967 |
| Debian:13 | wolfssl | 5.7.2-0.1+deb13u2 | DEBIAN-CVE-2026-55967 |
| Ubuntu:22.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-55967 |
| Ubuntu:24.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-55967 |
| Ubuntu:25.10 | wolfssl | no fix listed | UBUNTU-CVE-2026-55967 |
| Ubuntu:26.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-55967 |
| Ubuntu:26.10 | wolfssl | no fix listed | UBUNTU-CVE-2026-55967 |
Affected products (as reported)
Weakness: CWE-323 · Vector: CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N