CVE-2026-82078: PaperCut NG/MF Unsafe Reflection Vulnerability
Summary
PaperCut NG/MF has an unsafe reflection vulnerability that allows attackers to execute arbitrary Java bytecode on the server process. This flaw can be chained with another vulnerability, CVE-2026-81578, and requires immediate mitigation according to vendor instructions and CISA guidance.
IFF Assessment
This vulnerability allows attackers to execute arbitrary code, posing a significant risk to system security and defender's ability to protect their networks.
Severity
This vulnerability has a high attack vector (Network), is fully exploitable, and allows for significant impact including complete compromise of confidentiality, integrity, and availability by executing arbitrary Java bytecode under the server process's security context.
CISA KEV: Listed as actively exploited. Federal patch due: September 14, 2026. Known ransomware use: Unknown.
Defender Context
Defenders should prioritize patching or mitigating this critical vulnerability in PaperCut NG/MF installations, as it allows for remote code execution. The chaining with another CVE increases the urgency, and it's crucial to follow vendor guidance and CISA directives for remediation to prevent potential exploitation, especially by ransomware.