{"id":"CVE-2026-81578","aliases":["EUVD-2026-67713","GHSA-44wc-j6f2-7fjr"],"status":"published","title":"PaperCut MF/NG: Authentication Bypass","description":"An improper access control vulnerability exists in the web management interface of PaperCut MF and PaperCut NG. Under specific conditions, unauthenticated remote requests targeting administrative functions can trigger backend actions prior to the  completion of access validation checks. This allows an unauthenticated remote attacker to modify certain system configurations.","severity":{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.84734,"percentile":0.99712,"model":"v2026.06.15"},"facts":{"in_kev":true,"known_exploited":true,"public_exploit":true,"fix_available":false},"cwes":["CWE-305","CWE-306"],"published":"2026-08-28T11:39:45Z","modified":"2026-09-14T00:16:56Z","kev":{"date_added":"2026-08-31","due_date":"2026-09-14","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.","known_ransomware_use":"Unknown"},"exploitation":[{"source":"euvd","since":"2026-08-27"},{"source":"kev","since":"2026-08-31"}],"exploits":[{"source":"metasploit","id":"exploit/multi/http/papercut_ng_external_user_lookup_rce","title":"PaperCut NG/MF Unauthenticated RCE (CVE-2026-81578 + CVE-2026-82078)","type":"exploit","platform":"Java,Linux,Unix,Windows","date":"2026-08-27","verified":true,"url":"https://www.rapid7.com/db/modules/exploit/multi/http/papercut_ng_external_user_lookup_rce"},{"source":"pocgithub","id":"virologi-info/papercut-toolkit","title":"virologi-info/papercut-toolkit","date":"2026-08-29","url":"https://github.com/virologi-info/papercut-toolkit"},{"source":"pocgithub","id":"yora1928/PaperCut-CVE-2026-81578-82078","title":"yora1928/PaperCut-CVE-2026-81578-82078","date":"2026-08-29","url":"https://github.com/yora1928/PaperCut-CVE-2026-81578-82078"},{"source":"nuclei","id":"CVE-2026-81578","title":"PaperCut NG/MF \u003c=26.0.4 - Unauthenticated ConfigEditor Access via Tapestry Complex-Direct","type":"detection template","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-81578.yaml"}],"products":[{"vendor":"papercut","product":"ng/mf"},{"vendor":"papercut","product":"papercut mf/ng"},{"vendor":"papercut","product":"papercut_mf"},{"vendor":"papercut","product":"papercut_ng"}],"references":[{"url":"https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/","tags":["Patch","Vendor Advisory"]},{"url":"https://github.com/rapid7/metasploit-framework/pull/21842","tags":["exploit","Issue Tracking","Patch"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-81578","tags":["government-resource","Patch","Third Party Advisory","US Government Resource"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-81578"},{"url":"https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory"},{"url":"https://github.com/advisories/GHSA-44wc-j6f2-7fjr"}],"sources":{"cve":[{"id":"CVE-2026-81578","title":"PaperCut MF/NG: Authentication Bypass","description":"An improper access control vulnerability exists in the web management interface of PaperCut MF and PaperCut NG. Under specific conditions, unauthenticated remote requests targeting administrative functions can trigger backend actions prior to the  completion of access validation checks. This allows an unauthenticated remote attacker to modify certain system configurations.","status":"published","published":"2026-08-28T11:39:45.402Z","modified":"2026-09-13T23:15:33.997Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-305"],"updated_at":"2026-11-02T13:36:18.075535Z"}],"euvd":[{"id":"EUVD-2026-67713","description":"An improper access control vulnerability exists in the web management interface of PaperCut MF and PaperCut NG. Under specific conditions, unauthenticated remote requests targeting administrative functions can trigger backend actions prior to the  completion of access validation checks. This allows an unauthenticated remote attacker to modify certain system configurations.","status":"published","published":"2026-08-28T11:39:45Z","modified":"2026-09-13T23:15:33Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high"}],"exploited_since":"2026-08-27","updated_at":"2026-11-02T17:28:21.556158Z"}],"ghsa":[{"id":"GHSA-44wc-j6f2-7fjr","title":"An improper access control vulnerability exists in the web management interface of PaperCut MF...","description":"An improper access control vulnerability exists in the web management interface of PaperCut MF and PaperCut NG. Under specific conditions, unauthenticated remote requests targeting administrative functions can trigger backend actions prior to the  completion of access validation checks. This allows an unauthenticated remote attacker to modify certain system configurations.","status":"published","published":"2026-08-28T18:31:30Z","modified":"2026-08-31T21:31:56Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-305"],"updated_at":"2026-11-02T15:11:11.962153Z"}],"kev":[{"id":"CVE-2026-81578","title":"PaperCut NG/MF Missing Authentication for Critical Function Vulnerability","description":"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.","cwes":["CWE-306"],"kev":{"date_added":"2026-08-31","due_date":"2026-09-14","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.","known_ransomware_use":"Unknown"},"updated_at":"2026-11-02T17:00:15.999436Z"}],"nvd":[{"id":"CVE-2026-81578","description":"An improper access control vulnerability exists in the web management interface of PaperCut MF and PaperCut NG. Under specific conditions, unauthenticated remote requests targeting administrative functions can trigger backend actions prior to the  completion of access validation checks. This allows an unauthenticated remote attacker to modify certain system configurations.","status":"published","published":"2026-08-28T16:18:29.6Z","modified":"2026-09-14T00:16:56.207Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"}],"cwes":["CWE-305"],"updated_at":"2026-11-02T14:12:42.366888Z"}]}}