CVE-2025-27558 is a critical vulnerability affecting mesh networks that implement the upcoming IEEE 802.11 standard revision P802.11-REVme (draft versions D1.1 through D7.0). This vulnerability is a variant of the FragAttacks class of Wi-Fi attacks, which exploit flaws in the fragmentation and aggregation mechanisms of Wi-Fi frames. Specifically, the issue arises in mesh networks using Wi-Fi Protected Access protocols (WPA, WPA2, WPA3) or the deprecated Wired Equivalent Privacy (WEP) when devices support receiving non-SSP (non-Strict Sequence Protection) A-MSDU (Aggregated MAC Service Data Unit) frames. An attacker can inject arbitrary frames into the network, potentially leading to unauthorized data injection or manipulation. The root cause is an incorrect fix applied to a previous vulnerability (CVE-2020-24588), indicating that the patch did not fully address the underlying protocol flaw. Since P802.11-REVme is a planned release of the 802.11 standard as of early 2025, this vulnerability affects devices implementing these draft versions or early adopters of the new standard. The CVSS v3.1 score of 9.1 reflects the high impact and ease of exploitation, as the attack requires no privileges or user interaction and can be performed remotely over the network. The vulnerability impacts confidentiality and integrity but does not affect availability. No known exploits are currently in the wild, and no patches have been released yet, as the standard is still in draft form. The CWE-345 classification indicates improper verification of data authenticity, which aligns with the frame injection capability.

For European organizations, this vulnerability poses a significant risk to the security of mesh Wi-Fi networks, which are increasingly deployed in enterprise, industrial, and public infrastructure settings for their scalability and resilience. Successful exploitation could allow attackers to inject malicious frames, leading to data interception, manipulation, or unauthorized commands within the mesh network. This could compromise sensitive communications, disrupt network operations, or facilitate lateral movement within internal networks. Critical infrastructure sectors such as transportation, energy, healthcare, and government agencies that rely on mesh Wi-Fi for operational technology or secure communications are particularly at risk. The vulnerability undermines the confidentiality and integrity of wireless communications, potentially exposing organizations to espionage, data breaches, or sabotage. Given the lack of patches and the complexity of the standard, mitigation may be challenging in the short term, increasing the window of exposure.

Organizations should proactively assess their current and planned Wi-Fi mesh deployments for the use of draft or early versions of the P802.11-REVme standard. Until official patches or updated standards are released, it is advisable to avoid deploying devices that implement these draft versions. For existing mesh networks, disabling support for non-SSP A-MSDU frames, if configurable, can reduce exposure. Network segmentation and strict access controls should be enforced to limit the impact of any frame injection. Monitoring for anomalous Wi-Fi frame activity using advanced wireless intrusion detection systems (WIDS) can help detect exploitation attempts. Additionally, organizations should maintain close communication with device vendors and standard bodies to obtain timely updates and patches once available. Implementing robust encryption and authentication mechanisms at higher network layers can provide defense-in-depth against injected frames. Finally, organizations should prepare incident response plans specific to wireless network attacks to quickly contain and remediate any incidents.