CISA KEV 31 Aug 2026: 2 exploited flaws in PaperCut
2 vulnerabilities
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On 31 August 2026, CISA added 2 actively exploited vulnerabilities affecting PaperCut to its Known Exploited Vulnerabilities catalog. If you run any of these products, patch or mitigate now — exploitation is already happening.
KEV deadlines bind US federal agencies only, but a listing means attackers are already using the flaw, so treat it as a patch-now signal. If one of these products in your organisation was compromised, CERT-In's directions of 28 April 2022 require service providers, intermediaries, data centres, companies and government organisations to report specified incidents within 6 hours of noticing them. How to report an incident to CERT-In.
The vulnerabilities
CVE-2026-81578Federal deadline
PaperCut NG/MF Missing Authentication for Critical Function Vulnerability
PaperCut / NG/MF / CWE-306
PaperCut NG/MF contains a missing authentication for critical function vulnerability which allows an unauthenticated remote attacker to modify certain system configurations. This vulnerability can be chained with CVE-2026-82078.
Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. CISA links: BOD 26-04 · Forensics Triage Requirements
PaperCut NG/MF contains an unsafe reflection vulnerability that allows an attacker to manipulate system configuration parameters and execute arbitrary Java bytecode residing on the application classpath under the security context of the PaperCut server process. This vulnerability can be chained with CVE-2026-81578.
Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. CISA links: BOD 26-04 · Forensics Triage Requirements
