How severe is CVE-2026-81578?

CVE-2026-81578 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-81578 being actively exploited?

Yes. CVE-2026-81578 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-08-31, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2026-81578?

CVE-2026-81578 primarily affects Papercut Papercut Mf. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-81578?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

When was CVE-2026-81578 published?

CVE-2026-81578 was published on 2026-08-28 and last updated on 2026-09-14.

CVE-2026-81578

CVE-2026-81578 is a critical-severity vulnerability in Papercut Papercut Mf with a CVSS 3.x base score of 9.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2026-08-31). The underlying weakness is classified as CWE-305.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 8.8
EPSS exploit prediction: 3% (88th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2026-08-31)
Weakness: CWE-305
Affected product: Papercut Papercut Mf
Published: 2026-08-28
Last modified: 2026-09-14

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.

Frequently asked questions

What is CVE-2026-81578?: 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.
How severe is CVE-2026-81578?: CVE-2026-81578 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-81578 being actively exploited?: Yes. CVE-2026-81578 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-08-31, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2026-81578?: CVE-2026-81578 primarily affects Papercut Papercut Mf. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-81578?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
When was CVE-2026-81578 published?: CVE-2026-81578 was published on 2026-08-28 and last updated on 2026-09-14.

References

Affected products (2)

cpe:2.3:a:papercut:papercut_mf:*:*:*:*:*:*:*:*
cpe:2.3:a:papercut:papercut_ng:*:*:*:*:*:*:*:*

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