Critical Zero-Day Vulnerabilities in PaperCut Software Exploited in Active Attacks Prompt Emergency Security Response

Print software developer PaperCut has issued emergency security patches after uncovering active exploitation of zero-day vulnerabilities affecting all versions of its PaperCut NG and PaperCut MF applications. Discovered in late August 2026, the security flaws—tracked as CVE-2026-81578 and CVE-2026-82078—allow unauthenticated remote attackers to modify system configurations and execute arbitrary code on vulnerable servers. According to technical advisories released by cybersecurity research firms and the U.S. Cybersecurity and Infrastructure Security Agency (CISA), threat actors are chaining these vulnerabilities together to bypass authentication controls. Once access is gained, malicious actors have been observed covertly installing remote management tools onto compromised application servers to maintain persistent control over internal networks. CISA formally added the vulnerabilities to its Known Exploited Vulnerabilities catalog on August 31, 2026, establishing a mandatory mitigation deadline for government and enterprise networks. The breach poses significant risks for educational institutions, corporate enterprises, and government agencies that deploy PaperCut for print management. Security experts recommend that network administrators restrict public internet access to PaperCut web interfaces immediately and apply the latest emergency software updates to mitigate unauthorized access and potential data extortion.