CVE-2026-59847

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

Published Jul 21, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

Vendor Workaround

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

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4844-1 libssh security update
Debian DSA Debian DSA DSA-6410-1 libssh security update
Ubuntu USN Ubuntu USN USN-8699-1 libssh vulnerabilities
History
Type Values Removed Values Added
CPEs cpe:2.3:a:libssh:libssh:-:*:*:*:*:*:*:* cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:*
cpe:2.3:a:libssh:libssh:0.12.0:*:*:*:*:*:*:*
Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
cpe:/a:redhat:enterprise_linux:8::appstream
cpe:/a:redhat:enterprise_linux:9::appstream
cpe:/o:redhat:enterprise_linux:8::baseos
cpe:/o:redhat:enterprise_linux:9::baseos
References
Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:10 cpe:/o:redhat:enterprise_linux:10.2
References
Type Values Removed Values Added
Weaknesses CWE-253
Type Values Removed Values Added
First Time appeared Libssh
Libssh libssh
Redhat hardened Images
Vendors & Products Libssh
Libssh libssh
Redhat hardened Images
Type Values Removed Values Added
Weaknesses CWE-1310
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title Libssh: libssh: integrity downgrade via openssl aes-gcm tag verification
First Time appeared Redhat
Redhat enterprise Linux
Redhat hummingbird
CPEs cpe:/a:redhat:hummingbird:1
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Redhat hummingbird
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Sep 1, 2026, 8:01 PM
Reserved
Jul 7, 2026, 3:40 PM
Status
Analyzed
Published
Jul 21, 2026, 2:16 PM
Modified
Sep 4, 2026, 7:23 PM
Severity
Moderate
Public date
Jul 21, 2026, 1:02 PM