CVE-2025-5318 is a medium-severity vulnerability identified in the libssh library used within Red Hat Enterprise Linux 10. The flaw is an out-of-bounds read occurring in the sftp_handle function. This vulnerability arises due to an incorrect comparison check that allows the function to access memory beyond the valid handle list boundaries. Consequently, the function may return an invalid pointer, which is subsequently used in further processing. An authenticated remote attacker exploiting this flaw can potentially read unintended memory regions. This could lead to exposure of sensitive information stored in memory or cause abnormal service behavior. The vulnerability requires the attacker to have valid authentication credentials to the SSH service, but no user interaction is needed beyond that. The CVSS v3.1 base score is 5.4, reflecting a medium severity level, with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), privileges required (PR:L), no user interaction (UI:N), unchanged scope (S:U), and low impact on confidentiality and integrity (C:L/I:L), with no impact on availability (A:N). No known exploits are currently reported in the wild, and no patches or mitigations are linked yet. The flaw specifically affects Red Hat Enterprise Linux 10 installations that utilize the vulnerable libssh version for SFTP operations.

For European organizations running Red Hat Enterprise Linux 10, particularly those using libssh for SFTP services, this vulnerability poses a risk of unauthorized disclosure of sensitive data. Since exploitation requires valid authentication, the threat is primarily to environments where user credentials might be compromised or weakly protected. The out-of-bounds read could allow attackers to access memory areas containing confidential information, potentially including cryptographic keys, user data, or system secrets. While the vulnerability does not directly impact system availability or integrity, the exposure of sensitive information can lead to further attacks such as privilege escalation or lateral movement within networks. Organizations in sectors with stringent data protection requirements, such as finance, healthcare, and government, could face compliance and reputational risks if sensitive data is leaked. The absence of known exploits reduces immediate risk, but the medium severity and network accessibility mean that proactive mitigation is important to prevent future exploitation.

European organizations should immediately audit their Red Hat Enterprise Linux 10 systems to identify usage of the vulnerable libssh library, especially for SFTP services. Until an official patch is released, organizations can mitigate risk by restricting SSH access to trusted networks and enforcing strong authentication mechanisms, such as multi-factor authentication and robust password policies, to reduce the likelihood of credential compromise. Monitoring SSH logs for unusual authentication attempts or anomalous SFTP activity can help detect exploitation attempts. Network segmentation should be employed to limit exposure of critical systems running the vulnerable software. Additionally, organizations should prepare to apply vendor patches promptly once available and consider temporarily disabling or restricting SFTP functionality if feasible. Employing memory protection mechanisms and runtime security tools that detect out-of-bounds memory access may provide additional defense layers. Finally, educating system administrators about this vulnerability and ensuring timely updates to vulnerability management systems will support effective risk management.