CVE-2026-81578

CRITICALNVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score elevated to 9.8 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-08-31), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 9.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 4 sources updated this weekExploited in the wild
9.8EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 3%CVSS: 9.8Exploit: cisa kev · ssvc active · Metasploit · public exploitExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
99(Attend)
EG Risk 99/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation100% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
3%
EPSS %ILE
88%
KEV
⚠ Exploited

Published

August 28, 2026

Last Modified

September 14, 2026

Advisory Details (3)

Auto-updated Sep 14, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: github_pr, cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-81578
github_pr

Add exploit module for the recent PaperCut MF/NG 0day (CVE-2026-81578 + CVE-2026-82078)

Fix merged in rapid7/metasploit-framework PR #21842 on 2026-09-03 — awaiting tagged release

https://github.com/rapid7/metasploit-framework/pull/21842
generic

URGENT Security Advisory: PaperCut NG/MF Security Bulletin (27 Aug 2026) | PaperCut

https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/

Vendor Advisories for CVE-2026-81578(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 57× in last 7d / 188× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 188 total refreshes for this CVE.

  1. 2026-09-19 11:38 UTCGHSA enrichment
  2. 2026-09-19 07:21 UTCGHSA enrichment
  3. 2026-09-19 03:07 UTCGHSA enrichment
  4. 2026-09-18 22:53 UTCEG score recompute
  5. 2026-09-18 22:53 UTCGHSA enrichment
  6. 2026-09-18 19:28 UTCEPSS rescore
  7. 2026-09-18 19:20 UTCCISA KEV update
  8. 2026-09-18 18:40 UTCGHSA enrichment
  9. 2026-09-18 14:26 UTCGHSA enrichment
  10. 2026-09-18 14:15 UTCCISA KEV update
  11. 2026-09-18 10:12 UTCGHSA enrichment
  12. 2026-09-18 05:58 UTCGHSA enrichment
  13. 2026-09-18 01:44 UTCGHSA enrichment
  14. 2026-09-17 21:30 UTCEG score recompute
  15. 2026-09-17 21:30 UTCGHSA enrichment
  16. 2026-09-17 17:15 UTCGHSA enrichment
  17. 2026-09-17 13:01 UTCGHSA enrichment
  18. 2026-09-17 08:47 UTCGHSA enrichment
  19. 2026-09-17 04:33 UTCGHSA enrichment
  20. 2026-09-17 00:19 UTCGHSA enrichment
  21. 2026-09-16 20:05 UTCGHSA enrichment
  22. 2026-09-16 15:51 UTCEG score recompute
  23. 2026-09-16 15:51 UTCGHSA enrichment
  24. 2026-09-16 14:10 UTCCISA KEV update
  25. 2026-09-16 14:08 UTCEPSS rescore
Show 75 more
  1. 2026-09-16 11:37 UTCGHSA enrichment
  2. 2026-09-16 07:23 UTCEG score recompute
  3. 2026-09-16 07:23 UTCGHSA enrichment
  4. 2026-09-16 05:15 UTCEPSS rescore
  5. 2026-09-16 03:09 UTCGHSA enrichment
  6. 2026-09-15 22:54 UTCGHSA enrichment
  7. 2026-09-15 18:40 UTCGHSA enrichment
  8. 2026-09-15 14:26 UTCGHSA enrichment
  9. 2026-09-15 10:12 UTCGHSA enrichment
  10. 2026-09-15 05:58 UTCEG score recompute
  11. 2026-09-15 05:58 UTCGHSA enrichment
  12. 2026-09-15 03:12 UTCEPSS rescore
  13. 2026-09-15 03:12 UTCEPSS rescore
  14. 2026-09-15 01:44 UTCGHSA enrichment
  15. 2026-09-14 21:30 UTCGHSA enrichment
  16. 2026-09-14 19:24 UTCCISA KEV update
  17. 2026-09-14 17:16 UTCGHSA enrichment
  18. 2026-09-14 13:02 UTCGHSA enrichment
  19. 2026-09-14 08:48 UTCGHSA enrichment
  20. 2026-09-14 04:34 UTCGHSA enrichment
  21. 2026-09-14 00:20 UTCGHSA enrichment
  22. 2026-09-13 23:20 UTCGHSA enrichment
  23. 2026-09-13 22:09 UTCGHSA enrichment
  24. 2026-09-13 17:55 UTCEG score recompute
  25. 2026-09-13 17:55 UTCGHSA enrichment
  26. 2026-09-13 13:41 UTCGHSA enrichment
  27. 2026-09-13 09:27 UTCGHSA enrichment
  28. 2026-09-13 05:13 UTCGHSA enrichment
  29. 2026-09-13 00:59 UTCGHSA enrichment
  30. 2026-09-12 20:45 UTCGHSA enrichment
  31. 2026-09-12 16:31 UTCEG score recompute
  32. 2026-09-12 16:31 UTCGHSA enrichment
  33. 2026-09-12 12:17 UTCGHSA enrichment
  34. 2026-09-12 08:03 UTCGHSA enrichment
  35. 2026-09-12 03:49 UTCGHSA enrichment
  36. 2026-09-11 23:35 UTCGHSA enrichment
  37. 2026-09-11 19:21 UTCGHSA enrichment
  38. 2026-09-11 18:49 UTCCISA KEV update
  39. 2026-09-11 15:07 UTCEG score recompute
  40. 2026-09-11 15:07 UTCGHSA enrichment
  41. 2026-09-11 14:53 UTCEPSS rescore
  42. 2026-09-11 14:53 UTCEPSS rescore
  43. 2026-09-11 10:53 UTCEG score recompute
  44. 2026-09-11 10:53 UTCGHSA enrichment
  45. 2026-09-11 06:39 UTCGHSA enrichment
  46. 2026-09-11 02:25 UTCGHSA enrichment
  47. 2026-09-10 22:11 UTCGHSA enrichment
  48. 2026-09-10 19:28 UTCCISA KEV update
  49. 2026-09-10 17:56 UTCGHSA enrichment
  50. 2026-09-10 13:42 UTCEG score recompute
  51. 2026-09-10 13:42 UTCGHSA enrichment
  52. 2026-09-10 09:28 UTCGHSA enrichment
  53. 2026-09-10 05:13 UTCGHSA enrichment
  54. 2026-09-10 00:59 UTCGHSA enrichment
  55. 2026-09-09 20:45 UTCGHSA enrichment
  56. 2026-09-09 19:08 UTCCISA KEV update
  57. 2026-09-09 16:31 UTCGHSA enrichment
  58. 2026-09-09 12:15 UTCGHSA enrichment
  59. 2026-09-09 08:00 UTCGHSA enrichment
  60. 2026-09-09 03:46 UTCGHSA enrichment
  61. 2026-09-08 23:32 UTCEG score recompute
  62. 2026-09-08 23:32 UTCGHSA enrichment
  63. 2026-09-08 22:01 UTCEPSS rescore
  64. 2026-09-08 19:17 UTCGHSA enrichment
  65. 2026-09-08 18:54 UTCCISA KEV update
  66. 2026-09-08 15:01 UTCGHSA enrichment
  67. 2026-09-08 10:45 UTCGHSA enrichment
  68. 2026-09-08 06:31 UTCGHSA enrichment
  69. 2026-09-08 02:15 UTCGHSA enrichment
  70. 2026-09-07 22:01 UTCGHSA enrichment
  71. 2026-09-07 17:47 UTCEG score recompute
  72. 2026-09-07 17:47 UTCGHSA enrichment
  73. 2026-09-07 13:32 UTCGHSA enrichment
  74. 2026-09-07 09:18 UTCGHSA enrichment
  75. 2026-09-07 05:04 UTCGHSA enrichment

Publicly available exploits

(4 references)

Working exploit code is in the public domain (1 Metasploit module) (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCyora1928/PaperCut-CVE-2026-81578-82078
    First seen Aug 29, 2026

    Security research tool for PaperCut CVE-2026-81578 & CVE-2026-82078

    Open source ↗
  • GitHub PoCvirologi-info/papercut-toolkit
    First seen Aug 29, 2026

    #PaperCut CVE-2026-81578 + CVE-2026-82078 Defense Toolkit 2 3 A **defensive** toolkit to check and understand exposure to the chained

    Open source ↗
  • Metasploitexploit/multi/http/papercut_ng_external_user_lookup_rce✓ verified
    First seen Aug 27, 2026

    PaperCut NG/MF Unauthenticated RCE (CVE-2026-81578 + CVE-2026-82078)

    Open source ↗
  • Nucleihttp/cves/2026/CVE-2026-81578.yaml
    First seen Jan 1, 2026

    PaperCut NG/MF <=26.0.4 - Unauthenticated ConfigEditor Access via Tapestry Complex-Direct

    Open source ↗

Frequently asked(6)

What is CVE-2026-81578?
CVE-2026-81578 is a critical vulnerability published on August 28, 2026. 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…
When was CVE-2026-81578 disclosed?
CVE-2026-81578 was first published in the National Vulnerability Database on August 28, 2026, with the most recent update on September 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81578 actively exploited?
Yes. CISA added CVE-2026-81578 to the Known Exploited Vulnerabilities catalog on August 31, 2026, affecting PaperCut NG/MF. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2026-81578?
CVE-2026-81578 has a CVSS v3 base score of 9.8 (NVD).
Which products are affected by CVE-2026-81578?
CVE-2026-81578 affects PaperCut NG/MF. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2026-81578?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81578, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-81578

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