Bug 2498180 (CVE-2026-59847)

Summary: CVE-2026-59847 libssh: libssh: integrity downgrade via OpenSSL AES-GCM tag verification
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, security-response-team, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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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.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2503671    
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Description OSIDB Bzimport 2026-07-08 18:22:46 UTC 
A flaw was found in libssh builds using the OpenSSL backend for AES-GCM. In the decrypt path in src/libcrypto.c, the return value from EVP_DecryptFinal() was checked incorrectly, so authentication tag verification failures were not handled as integrity failures. This could effectively remove integrity protection for affected AES-GCM sessions and allow an in-path attacker to modify plaintext on the wire without detection.
Comment 2 errata-xmlrpc 2026-08-17 20:53:28 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:55855 https://access.redhat.com/errata/RHSA-2026:55855