The vulnerability lies in libssh’s use of the OpenSSL backend, where incorrect AES‑GCM finalization checks can effectively disable integrity protection. An attacker who can intercept SSH traffic may alter the plaintext being transmitted without the alteration being detected by the recipient. The flaw creates a potential for undetected data tampering on the wire and is classified as CWE‑1310, a failure to perform required checks on sensitive data.

Affected products include Red Hat Enterprise Linux 10, 8, 9, and Red Hat Hardened Images, all of which ship the vulnerable libssh library in their default packages. The associated CPEs list the Hummingbird service and the RHEL operating systems for versions 8 through 10. Users running these distributions without a newer libssh layer are at risk.

The CVSS score of 5.9 indicates moderate severity, and the EPSS score of less than 1% suggests a low current exploitation probability. The vulnerability is not listed in CISA’s KEV catalog, but its nature allows an in‑path attacker—someone capable of intercepting or modifying traffic between an SSH client and server—to leverage the issue. No public exploit reports are known, but the combination of the weak integrity check and common SSH usage means the risk warrants timely remediation. The only mitigation offered by the vendor is to disable the aes128-gcm@openssh.com and aes256-gcm@openssh.com ciphers, after which the integrity guarantees of the remaining algorithms remain intact.