CVE-2026-82078
PaperCut NG/MF Unsafe Reflection Vulnerability - [Actively Exploited]
Description
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.
INFO
Published Date :
Aug. 28, 2026, 4:18 p.m.
Last Modified :
Sept. 14, 2026, 12:16 a.m.
Remotely Exploit :
Yes !
Source :
eb41dac7-0af8-4f84-9f6d-0272772514f4
CISA KEV (Known Exploited Vulnerabilities)
For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.
PaperCut NG/MF contains an unsafe reflection vulnerability that allows an attacker to manipulate system configuration parameters and execute arbitrary Java bytecode residing on the application classpath under the security context of the PaperCut server process. This vulnerability can be chained with CVE-2026-81578.
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.
Unknown
https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/?lid=2oneu2wt0ct4 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-82078
Affected Products
The following products are affected by CVE-2026-82078
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | CRITICAL | eb41dac7-0af8-4f84-9f6d-0272772514f4 | ||||
| CVSS 4.0 | CRITICAL | eb41dac7-0af8-4f84-9f6d-0272772514f4 |
Solution
- Update PaperCut MF and NG to the latest version.
- Configure database driver instantiation with an allowlist.
- Validate system configuration parameters regularly.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-82078.
| URL | Resource |
|---|---|
| https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/ | Patch Vendor Advisory |
| https://github.com/rapid7/metasploit-framework/pull/21842 | Issue Tracking Patch |
| https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-82078 | Patch Third Party Advisory US Government Resource |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-82078 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-82078
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-82078 vulnerability anywhere in the article.
-
security.nl
'Vierhonderd organisaties wereldwijd gehackt via PaperCut-kwetsbaarheden'
Aanvallers zijn er onlangs in geslaagd om vierhonderd organisaties te hacken via kwetsbaarheden in PaperCut MF/NG. Dat meldt cybersecuritybedrijf GreyNoise op basis van eigen onderzoek. Op 27 augustus ... Read more
-
The Hacker News
PaperCut Replaces Emergency Patches With Fixes for Two Actively Exploited Flaws
PaperCut on Thursday released a new security maintenance release that replaces all previously published emergency patches that were pushed to address two security flaws that have come under active exp ... Read more
-
The Cyber Express
AI Agents Compromised 440 PaperCut Servers, Researchers Say
A threat intelligence firm says it watched a Russian-speaking attacker turn hundreds of AI agents loose on a print management platform and compromise 440 servers in 48 countries — including 11 organiz ... Read more
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The Hacker News
PaperCut Attacker Uses Hundreds of AI Agents to Compromise 440+ Instances
A suspected Russian-speaking cyber actor has been attributed to the use of artificial intelligence (AI) to devise exploits targeting a recently disclosed pair of security flaws in PaperCut NG/MF and b ... Read more
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The Hacker News
Attackers Exploit PaperCut Flaws to Steal Credentials From Schools and Universities
Threat actors are exploiting the newly disclosed PaperCut flaws to facilitate credential theft in attacks targeting the education sector in the U.S. and Europe. The Arctic Wolf Adversary Research Team ... Read more
-
security.nl
Tweehonderd PaperCut NG/MF-servers missen update voor aangevallen lek
Meer dan tweehonderd PaperCut NG/MF-servers, waaronder zeven in Nederland, missen een belangrijke beveiligingsupdate voor twee kwetsbaarheden waar aanvallers actief misbruik van maken. Via de beveilig ... Read more
-
The Cyber Express
PaperCut Issues Second Emergency Patch as Researchers Break Fix for Exploited Zero-Days
PaperCut released a second emergency patch last Friday, for two vulnerabilities in its NG and MF print management servers that attackers are already exploiting, after security researchers demonstrated ... Read more
-
The Hacker News
Attackers Chain Two PaperCut Flaws to Execute Code Without Authentication
Malicious actors are exploiting a newly patched security flaw in PaperCut NG and MF to execute arbitrary code on susceptible instances, as the company released a fresh emergency fix with additional ha ... Read more
The following table lists the changes that have been made to the
CVE-2026-82078 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by eb41dac7-0af8-4f84-9f6d-0272772514f4
Sep. 14, 2026
Action Type Old Value New Value Added Affected Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/82xxx/CVE-2026-82078.json">CVE-2026-82078</a> -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 01, 2026
Action Type Old Value New Value Changed SSVC {'id': 'CVE-2026-82078', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-31T15:25:19.545218Z'} {'id': 'CVE-2026-82078', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-28T00:00:00+00:00'} -
Initial Analysis by [email protected]
Aug. 31, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:a:papercut:papercut_mf:*:*:*:*:*:*:*:* versions up to (excluding) 24.1.9 *cpe:2.3:a:papercut:papercut_ng:*:*:*:*:*:*:*:* versions up to (excluding) 24.1.9 *cpe:2.3:a:papercut:papercut_mf:*:*:*:*:*:*:*:* versions from (including) 25.0.2 up to (excluding) 25.0.12 *cpe:2.3:a:papercut:papercut_mf:*:*:*:*:*:*:*:* versions from (including) 26.0.2 up to (excluding) 26.0.4 *cpe:2.3:a:papercut:papercut_ng:*:*:*:*:*:*:*:* versions from (including) 25.0.2 up to (excluding) 25.0.12 *cpe:2.3:a:papercut:papercut_ng:*:*:*:*:*:*:*:* versions from (including) 26.0.2 up to (excluding) 26.0.4 Added Reference Type PaperCut: https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/ Types: Patch, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/rapid7/metasploit-framework/pull/21842 Types: Issue Tracking, Patch Added Reference Type CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-82078 Types: Patch, Third Party Advisory, US Government Resource -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 31, 2026
Action Type Old Value New Value Changed SSVC {'id': 'CVE-2026-82078', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-31T12:33:45.803363Z'} {'id': 'CVE-2026-82078', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-31T15:25:19.545218Z'} -
CVE CISA KEV Update by 9119a7d8-5eab-497f-8521-727c672e3725
Aug. 31, 2026
Action Type Old Value New Value Added Date Added 2026-08-31 Added Due Date 2026-08-31 Added Required Action 2026-08-31 Added Vulnerability Name 2026-08-31 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 31, 2026
Action Type Old Value New Value Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-82078 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 31, 2026
Action Type Old Value New Value Added Reference https://github.com/rapid7/metasploit-framework/pull/21842 Changed SSVC {'id': 'CVE-2026-82078', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-28T00:00:00+00:00'} {'id': 'CVE-2026-82078', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-31T12:33:45.803363Z'} -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 29, 2026
Action Type Old Value New Value Changed SSVC {'id': 'CVE-2026-82078', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-28T15:35:13.512853Z'} {'id': 'CVE-2026-82078', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-28T00:00:00+00:00'} -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 28, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-82078', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-28T15:35:13.512853Z'} -
New CVE Received by eb41dac7-0af8-4f84-9f6d-0272772514f4
Aug. 28, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V4.0 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 Added CWE CWE-470 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/82xxx/CVE-2026-82078.json">CVE-2026-82078</a> Added Reference https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/