Is CVE-2026-81578 actively exploited?

Yes. Previdian tracks CVE-2026-81578 as a known exploited vulnerability. Confidence is high.

What exploitation activity has Previdian observed?

Previdian has not yet recorded sensor-observed exploitation attempts for CVE-2026-81578. Our sensors continue to monitor for activity targeting this CVE.

Which versions are affected?

CVE-2026-81578 affects PaperCut PaperCut MF/NG. Reported affected version: 0 to < 24.1.10, 25.0.13, 26.0.5.

No. CVE-2026-81578 is not currently listed in CISA KEV.

Vulnerability report

Exploited in the wild High confidence Not in CISA KEV

CVE-2026-81578

Q: How should organizations remediate it?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Q: Is it in CISA KEV?

No. CVE-2026-81578 is not currently listed in CISA KEV.

PaperCut MF/NG Authentication Bypass Authentication Bypass

PaperCut / PaperCut MF/NG · affected before 24.1.10, 25.0.13, 26.0.5

View live feed Monitor via API Watch CVE

Severity: CVSS 8.8 · High
Confidence: High
Exploit status: Exploited in the wild
EPSS: —
First observed: —
Last observed: —

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-81578 is an unauthenticated vulnerability affecting PaperCut PaperCut MF/NG. An improper access control vulnerability exists in the web management interface of PaperCut MF and PaperCut NG. Under...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is high. Also confirmed by third-party sources.

Who is affected?

PaperCut / PaperCut MF/NG affected before 24.1.10, 25.0.13, 26.0.5.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

An improper access control vulnerability exists in the web management interface of PaperCut MF and PaperCut NG

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.

Vendor Product Affected Status

PaperCut PaperCut MF/NG Before 24.1.10, 25.0.13, 26.0.5 Affected

Published: 28 Aug 2026
Exploitation Reported: 27 Aug 2026
Attack vector: Remote
Complexity: Low
Privileges: None
User interaction: None

CVE References

CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2026-81578
papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent... papercut.com · CVE Record https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent...

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

PaperCut

Recorded 27 Aug 2026

Independent exploitation attestation added to the Previdian record.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access

Source	Added
PaperCut First	2026-08-27 15:39 UTC
Rapid7	2026-08-28 10:09 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets: 0
User-Agents: 0

Raw values available in Pro and Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v4.0

8.8 High

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

EPSS

—

Weaknesses

Authentication Bypass by Primary Weakness CWE-305

Recent mention · Rapid7

PaperCut NG/MF Critical Zero-Day Exploited in the Wild

Overview On August 27, 2026, PaperCut Software published an urgent security advisory stating that it is investigating active exploitation of a vulnerability affecting PaperCut NG and PaperCut MF. PaperCut has confirmed customer incidents and is treating the issue as a security...

Read full advisory

Timeline

From disclosure to observed exploitation

28 Aug 2026
CVE published

Vulnerability disclosed publicly
28 Aug 2026
KEV confirmed by Rapid7

Exploitation attested by an external source
27 Aug 2026
Added to Previdian KEV Feed

High-confidence, third-party attested exploitation
27 Aug 2026
CVE ID reserved

Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

View Pro pricing Read API docs

Evidence confidence and provenance
First-party sensor telemetry
PoC and scanner references
Affected versions and enrichment
Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-81578

Free JSON includes basic KEV fields

{
  "cve_id": "CVE-2026-81578",
  "confidence": "High",
  "cvss_score": 8.8,
  "cvss_estimated": false,
  "epss_score": null,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}

Early warning alerts

Get alerts on high-impact exploitation

Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.