CVE-2026-41409 -- CVSS 9.8 Vulnerability Briefing

CVE-2026-41409 | CVSS 9.8 (Critical) | Exploit: No known exploit

What Is It

CVE-2026-41409 is an incomplete fix vulnerability in Apache MINA, specifically in the AbstractIoBuffer.getObject() method, where a prior patch for CVE-2024-52046 failed to fully prevent unsafe Java deserialization.

Technical Detail

The original remediation for CVE-2024-52046 introduced a classname allowlist intended to restrict which classes could be deserialized via AbstractIoBuffer.getObject(); however, the allowlist enforcement was applied after a static initializer executed, leaving a window in which unsafe deserialization could still occur. An attacker capable of sending crafted data to a MINA-based service could supply a malicious serialized object that bypasses the allowlist check during that initialization phase. Successful exploitation could result in remote code execution on the affected host, inheriting the privileges of the MINA process.

Exploitation Status

No known exploit exists for this vulnerability at this time. It has not been added to the CISA Known Exploited Vulnerabilities catalog. While the CVSS score of 9.8 reflects the theoretical severity of the flaw, there is currently no public proof-of-concept code or confirmed in-the-wild exploitation reported as of May 4, 2026.

Who Is Targeting This

No specific threat actor attribution at this time. No campaigns or targeted sectors have been associated with this vulnerability in available intelligence sources.

What To Do

Organizations using Apache MINA should treat this as a high-priority patch given the critical CVSS score and the nature of the flaw as a bypass of a previously deployed security control. Apply the latest patched version of Apache MINA as released by the Apache Software Foundation, which addresses the incomplete fix. Until patching is complete, consider restricting network access to MINA-based services to trusted sources only, and monitor for anomalous deserialization activity or unexpected process spawning from MINA service processes. Review any prior mitigations applied for CVE-2024-52046 and do not treat them as sufficient protection against this bypass.