libssh AES-GCM finalization flaw removes integrity protection
CVE-2026-59847 Published on July 21, 2026

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

Vendor Advisory Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-59847 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity, and no impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
HIGH
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
HIGH
Availability Impact:
NONE

Timeline

Reported to Red Hat.

Made public. 83 days later.

Weakness Types

Incorrect Check of Function Return Value

The software incorrectly checks a return value from a function, which prevents the software from detecting errors or exceptional conditions. Important and common functions will return some value about the success of its actions. This will alert the program whether or not to handle any errors caused by that function.

Missing Ability to Patch ROM Code

Missing an ability to patch ROM code may leave a System or System-on-Chip (SoC) in a vulnerable state.


Products Associated with CVE-2026-59847

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Affected Versions

Red Hat Enterprise Linux 10: Red Hat Hardened Images: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: