CVE-2026-87078
📛 CVE Title
Net::IDN::Punycode versions from 2.302 before 2.590 for Perl leak the output buffer on every rejected label in decode_punycode
Description
Net::IDN::Punycode versions from 2.302 before 2.590 for Perl leak the output buffer on every rejected label in decode_punycode. The XS backend allocates the scalar it returns before it validates the input, sizing the buffer at twice the input length. The scalar is released only on the success path, so each of the three croaks that reject a label leaves the scalar and its buffer allocated. Nothing bounds the label length in the to-Unicode direction, since the 63-byte DNS limit is checked only when converting to ASCII. Only the XS backend is affected. A sender who supplies invalid labels grows the process by twice the label length per rejected call, with no successful call needed.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- CPANSec
- CVSS severity
- —
- CVSS score
- —
- CVSS vector
- —
- Effective score
- 9.1 / 10 CRITICAL source: NVD
- CWE(s)
-
CWE-401 - Reserved
- 2026-09-08
- Published
- 2026-09-22 07:19 UTC
- Last updated
- 2026-09-22 17:07 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/87xxx/CVE-2026-87078.json
- Linked Threat
- CVE-2026-87078 — Net::IDN::Punycode versions from 2.302 before 2.590 for Perl leak the output buffer on every rejected label in decode_punycode
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-09-22 08:16:40 UTC
- NVD last modified
- 2026-09-22 19:07:00 UTC
- NVD CVSS v3.1
- 9.1 / 10 CRITICAL source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
- NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H- Exploitability subscore
- 3.9 / 10
- Impact subscore
- 5.2 / 10
- EPSS score
- 0.0015 (probability of exploitation in next 30 days)
- EPSS percentile
- 4.98% vs all CVEs — higher = more likely to be exploited, as of 2026-09-22
NVD / KEV / EPSS data refreshed 2026-09-23 02:35 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-84291 - Assigner
- CPANSec
- Published
- Sep 22, 2026, 7:19:33 AM
- Updated
- Sep 22, 2026, 5:07:27 PM
- EUVD base score (CVSS 3.1)
-
9.1 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - EUVD-reported EPSS
- 0.1500
- Aliases
-
GHSA-xcgq-9mhw-ww57
ENISA description: Net::IDN::Punycode versions from 2.302 before 2.590 for Perl leak the output buffer on every rejected label in decode_punycode. The XS backend allocates the scalar it returns before it validates the input, sizing the buffer at twice the input length. The scalar is released only on the success path, so each of the three croaks that reject a label leaves the scalar and its buffer allocated. Nothing bounds the label length in the to-Unicode direction, since the 63-byte DNS limit is checked only when converting to ASCII. Only the XS backend is affected. A sender who supplies invalid labels grows the process by twice the label length per rejected call, with no successful call needed.
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| — | — |
2.302 (affected)
|
— |
Vendor references (3)
References embedded in the original CVE record by the assigning CNA.
Web references (0)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
No web references attached yet.
NVD-tagged references (4)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- http://www.openwall.com/lists/oss-security/2026/09/22/13 af854a3a-2127-422b-91ae-364da2661108
- https://github.com/robrwo/Net-IDN-Encode/commit/92572f726e48af5559de4cc8a831463b79dfb217.patch 9b29abf9-4ab0-4765-b253-1875cd9b441e
- https://github.com/robrwo/Net-IDN-Encode/commit/edad63e0eeeeb18d93bc6dfe4d9dcdff9c244e1b.patch 9b29abf9-4ab0-4765-b253-1875cd9b441e
- https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes 9b29abf9-4ab0-4765-b253-1875cd9b441e
Remediations (20)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:securityonline.info
PaperCut vulnerability CVE - 2026 -82078 is exploited in the wild. Attackers run malicious SQL for RCE and a Metasploit PoC is public. Patch now.
2026-09-23 15:42 UTC -
web:senserva.com
Every Microsoft security patch (KB) and the CVEs it fixes, with severity, CVSS, and CISA KEV status. Cross-linked to the CVE reference.
2026-09-23 15:42 UTC -
web:thecybersecguru.com
Active exploitation of PaperCut NG/MF pre-auth RCE ( CVE - 2026 -81578, CVE - 2026 -82078). Full chain analysis, IOCs, detection & emergency patch guidance
2026-09-23 15:42 UTC -
web:threatprotect.qualys.com
PaperCut released an Urgent Security Advisory to address two actively exploited vulnerabilities, tracked as CVE - 2026 -82078 & CVE - 2026 -81578, impacting all versions of PaperCut NG and PaperCut MF.
2026-09-23 15:42 UTC -
web:watchtowr.com
Patch immediately. Upgrade PaperCut NG/MF to the latest version and emergency patch , addressing CVE - 2026 -81578, CVE - 2026 -82078, and bypasses. Restart the PaperCut application service. Once forensic evidence has been captured, restart the service to remove in-memory implants. Patching alone does not remove an existing shell.
2026-09-23 15:42 UTC -
web:windowsforum.com
Microsoft published CVE - 2026 -62878 on August 11 as a Windows DNS Server Remote Code Execution Vulnerability, putting systems that run the Windows DNS Server role into the immediate patch -and-verify queue.
2026-09-23 15:42 UTC -
web:www.cisecurity.org
<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...
2026-09-23 15:42 UTC -
web:www.esentire.com
THE THREAT 2026 -09-02 Update: On September 1st, 2026 , PaperCut Software released Emergency Patch (Release 3) for customers with Internet-facing PaperCut NG/MF Application Servers that are unable to perform other mitigating actions. eSentire has observed incidents involving the…
2026-09-23 15:42 UTC -
web:www.helpnetsecurity.com
PaperCut Software has pinpointed the two vulnerabilities chained in these attacks and urged users to install a second patch .
2026-09-23 15:42 UTC -
web:www.sonicwall.com
PaperCut NG/MF Unauthenticated RCE ( CVE - 2026 -81578, CVE - 2026 -82078) OVERVIEW SonicWall Capture Labs threat research team became aware of the threats CVE - 2026 -81578 and CVE - 2026 -82078, assessed their impact, and developed mitigation measures.
2026-09-23 15:42 UTC -
web:blogs.oracle.com
For more information about the Critical Patch Update program, see the security vulnerability remediation practices page located on the Oracle Trust Center.
2026-09-25 10:07 UTC -
web:catalog.update.microsoft.com
Welcome to the Microsoft Update Catalog site. We want your feedback! Visit our newsgroup or send us an email to provide us with your thoughts and suggestions. To get started using the site, enter in your search terms in the Search box above or visit our FAQ for search tips. |Newsgroup|Send us your feedback
2026-09-25 10:07 UTC -
web:learn.microsoft.com
Unlike traditional cumulative updates that patch individual components, this update delivers the full .NET Framework 3.5 product as a standalone installer. It replaces any previously installed version.
2026-09-25 10:07 UTC -
web:support.microsoft.com
Be aware that the update in the Microsoft Download Center applies to the Microsoft Installer (.msi)-based edition of Office 2016. It doesn't apply to the Office 2016 Click-to-Run editions, such as Microsoft Office 365 Home. (See What version of Office am I using?) How to get and install the update Method 1: Microsoft Update This update is available from Microsoft Update. When you turn on ...
2026-09-25 10:07 UTC -
web:support.sap.com
SAP security Patch Day Bulletin This post shares the information on security notes that remediate vulnerabilities discovered in SAP products. SAP strongly recommends that the customer visits the support portal and applies patches on priority to protect their SAP landscape. On 9th of June 2026 , SAP security patch day saw the release of 15 new security notes.
2026-09-25 10:07 UTC -
web:ubuntu.com
Description Net::IDN::Punycode versions from 2.302 before 2.590 for Perl leak the output buffer on every rejected label in decode_punycode. The XS backend allocates the scalar it returns before it validates the input, sizing the buffer at twice the input length. The scalar is released only on the success path, so each of the three croaks that reject a label leaves the scalar and its buffer ...
2026-09-25 10:07 UTC -
web:windowsforum.com
Microsoft has published CVE - 2026 -62787, a Windows DNS Server Remote Code Execution Vulnerability, in its Security Update Guide as part of the August 11, 2026 security release.
2026-09-25 10:07 UTC -
web:www.computerworld.com
August's Patch Tuesday is a big one: 751 fixes, an exploited WinSock flaw and plenty of critical Windows, Office and Exchange issues.
2026-09-25 10:07 UTC -
web:www.oracle.com
This Critical Patch Update contains 1448 new security patches across the product families listed below. Please note that a My Oracle Support (MOS) note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at July 2026 Critical Patch Update: Executive Summary and Analysis.
2026-09-25 10:07 UTC -
web:www.oracle.com
Additional CVEs addressed are: The patch for CVE - 2026 -34481 also addresses CVE - 2026 -34477, CVE - 2026 -34478, CVE - 2026 -34479, and CVE - 2026 -34480. Oracle Fusion Middleware Risk Matrix This Critical Security Patch Update contains 106 new security patches for Oracle Fusion Middleware. 53 of these vulnerabilities may be remotely exploitable without authentication, i.e., may be exploited over a ...
2026-09-25 10:07 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-87078.json.
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