PaperCut security advisory (AV26-858) – Update 2
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
Serial number: AV26-858 Date: August 28, 2026 Updated: August 31, 2026 As of August 27, 2026, PaperCut is affected by vulnerabilities in the following products: PaperCut MF Prior to v24 Emergency Patch Release 2 Prior to v25 Emergency Patch Release 2 Prior to v26 Emergency Patch Release 2 PaperCut NG Prior to v24 Emergency Patch Release 2 Prior to v25 Emergency Patch Release 2 Prior to v26 Emergency Patch Release 2 Update 1 Open-source reporting indicates that CVE-2026-81578 and CVE-2026-82078 are related to PaperCut MF and PaperCut NG are being exploited in the wild. Update 2 On August 31, 2026, Cybersecurity and Infrastructure Security Agency (CISA) added CVE-2026-81578 and CVE-2026-82078 to their Known Exploited Vulnerabilities (KEV) Database. The Cyber Centre encourages users and administrators to review the provided web link and apply any necessary updates as they become available. URGENT Security Advisory: PaperCut NG/MF Security Bulletin (27 Aug 2026) CISA KEV: CVE-2026-81578 CISA KEV: CVE-2026-82078
CSIRTS triage
- What
- PaperCut has released emergency patches addressing vulnerabilities in MF and NG products.
- Who is affected
- Deployments running PaperCut MF or NG prior to the specified emergency patch releases.
- Urgency
- Urgent; official emergency patch advisory issued by vendor and cyber centre recommendation.
- Action
- Apply Emergency Patch Release 2 to all PaperCut MF and NG installations immediately.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://cyber.gc.ca/en/alerts-advisories/papercut-security-advisory-av26-858
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Exploitation confirmedCVE-2026-81578Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 53% of all EPSS-scored CVEs.
- Exploitation confirmedCVE-2026-82078Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 58% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-81578 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-82078 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- criticalexploitedCISA Adds Two Known Exploited Vulnerabilities to Catalogcisa
- unknownexploitedPaperCut Multiple Vulnerabilitieshkcert
- criticalexploitedCVE-2026-82078: PaperCut NG/MF Unsafe Reflection Vulnerabilitycisa-kev
- criticalexploitedCVE-2026-81578: PaperCut NG/MF Missing Authentication for Critical Function Vulnerabilitycisa-kev
- criticalexploitedCVE-2026-82078: An unsafe dynamic class loading vulnerability exists in the database connection utilities of P…nvd
- criticalexploitedCVE-2026-81578: An improper access control vulnerability exists in the web management interface of PaperCut MF…nvd
- unknownexploitedNCSC-2026-0334 [1.00] [M/H] Vulnerabilities patched in PaperCut MF and PaperCut NG from PaperCutncsc-nl
- unknownexploitedMultiple vulnerabilities in Papercut (August 28, 2026)cert-fr-avis
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