CVE-2025-5351 identifies a double free vulnerability within the libssh library's key export functionality as implemented in Red Hat Enterprise Linux 10. The vulnerability occurs in an internal function responsible for converting cryptographic keys into serialized formats. Specifically, during error handling, a memory structure is freed but not cleared, which can lead to a second free operation if another failure occurs later in the function's execution path. This double free condition can cause heap corruption, potentially leading to application instability or crashes, particularly in low-memory scenarios. The flaw requires network access (AV:N) and low privileges (PR:L) but does not require user interaction (UI:N). The attack complexity is high (AC:H), indicating exploitation is non-trivial. The impact on confidentiality and integrity is low, and availability impact is none, resulting in an overall CVSS score of 4.2 (medium severity). No known exploits have been reported in the wild, and no patches are linked yet, but the issue is publicly disclosed. The vulnerability affects systems performing key export operations using libssh, which is commonly used for secure communications and cryptographic key management in Red Hat Enterprise Linux 10 environments.

For European organizations, this vulnerability primarily threatens system reliability and stability rather than direct data compromise or service outages. Organizations relying on Red Hat Enterprise Linux 10 for critical infrastructure, secure communications, or cryptographic key management may experience application crashes or heap corruption under specific error conditions, especially when system memory is constrained. This could disrupt automated key export processes or services dependent on libssh, potentially causing operational delays or degraded security posture. Although the confidentiality and integrity impacts are low, repeated crashes or instability could indirectly affect availability and trust in security operations. The medium severity rating suggests that while immediate exploitation risk is limited, the vulnerability should be addressed promptly to maintain system robustness and prevent potential escalation or exploitation in complex attack chains.

European organizations should monitor Red Hat security advisories closely and apply patches or updates for Red Hat Enterprise Linux 10 as soon as they become available to address CVE-2025-5351. In the interim, auditing and limiting the use of key export functionality in libssh can reduce exposure. System administrators should review error handling and memory management practices in custom or third-party applications interfacing with libssh to detect and mitigate potential double free conditions. Implementing memory protection mechanisms such as Address Space Layout Randomization (ASLR) and heap integrity checks can help mitigate exploitation impact. Additionally, maintaining sufficient system memory and monitoring for unusual application crashes or instability related to cryptographic operations can aid early detection. Network segmentation and limiting access to services performing key exports can further reduce attack surface.