Vulnpedia
← All CVEs

CVE-2026-82078

CRITICAL 9.4 KNOWN EXPLOITED PoC CATALOGUED ALL-YEARS

Published 2026-08-28 · Last modified 2026-09-13 · PaperCut · NVD: Analyzed

An unsafe dynamic class loading vulnerability exists in the database connection utilities of PaperCut MF and PaperCut NG. The application instantiates database driver classes based on configurable driver names without validating against an allowlist of approved drivers. If an attacker can manipulate system configuration parameters, this enables the execution of arbitrary Java bytecode residing on the application classpath under the security context of the PaperCut server process.

ACTIVELY EXPLOITED

Confirmed exploited in the wild — in CISA KEV since 2026-08-31. Patch or mitigate now.

Exploitation likelihood

60.9%chance of exploitation in 30 days · 99th percentile

● In CISA KEV (2026-08-31)● Catalogued PoC◆ SSVC: exploitation active, automatable no

Impact if exploited

9.4CVSS 4.0 · CRITICAL · CNA

  • ConfidentialityHigh
  • IntegrityHigh
  • AvailabilityHigh

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ⚠Privileges: Requires an admin / high-privilege account
  • ✓User interaction: No user interaction needed
  • ✓Complexity: No special conditions — reliably repeatable
  • ✓Requirements: No special attack requirements

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

Public PoC or exploit resources are catalogued below.

Listed by the named source; Vulnpedia has not tested these resources.

PoC data: JSON

Resource commands

curl -s https://vulnpedia.com/cve/CVE-2026-82078/poc.jsonMachine-readable PoC index for this CVE (for automation).

Search for new PoCs

Search GitHub now — results may be empty or unverified.

Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Data snapshot:

Affected

Vendors Papercut

Products Papercut Mf/Ng Papercut Mf Papercut Ng

Weakness (CWE)

  • CWE-470: Use of Externally-Controlled input to select classes or code ('unsafe reflection')

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

References and research data (JSON)

Additional exploitation reports

Source-specific reports, separate from CISA KEV. Repeated observations from one source are not independent confirmations.

Known Affected Software Configurations

VendorProductVersion range
PapercutPapercut Mf< 24.1.9
PapercutPapercut Mf≥ 25.0.2 and < 25.0.12
PapercutPapercut Mf≥ 26.0.2 and < 26.0.4
PapercutPapercut Ng< 24.1.9
PapercutPapercut Ng≥ 25.0.2 and < 25.0.12
PapercutPapercut Ng≥ 26.0.2 and < 26.0.4

All CVSS metrics

  • CRITICAL 9.4 v4.0 · CNA Primary
    CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
  • CRITICAL 9.4 v4.0 · NVD Secondary
    CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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
  • CRITICAL 9.1 v3.1 · NVD Primary
    CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

References

Exploit-tagged references (not proof of a PoC)

Patches & mitigations

Advisories

Technical & other

Sources: NVD · CVE.org · All sources and attribution · EPSS