CVE-2026-59847 PUBLISHED

Libssh: libssh: integrity downgrade via openssl aes-gcm tag verification

Assigner: redhat
Reserved: 07.07.2026 Published: 21.07.2026 Updated: 21.07.2026

A flaw was found in libssh. Incorrect AES-GCM finalization checks in builds using the OpenSSL backend can effectively remove integrity protection, allowing an in-path attacker to modify plaintext on the wire without detection.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS Score: 5.9

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	High
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	Red Hat
Product	Red Hat Enterprise Linux 10
Versions	Default: affected

Vendor	Red Hat
Product	Red Hat Enterprise Linux 8
Versions	Default: affected

Vendor	Red Hat
Product	Red Hat Enterprise Linux 9
Versions	Default: affected

Vendor	Red Hat
Product	Red Hat Hardened Images
Versions	Default: affected

Workarounds

Disable the aes128-gcm@openssh.com and aes256-gcm@openssh.com ciphers.

Credits