CVE-2026-74765

Description

Net::IDN::Punycode versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode. The XS backend keeps the punycode delta, and the digit index derived from it, in a signed int. The accumulation `delta += (m-n) * (h+1)` has no overflow check, so a large enough code point wraps the delta and the digit index leaves the range of the 36-entry digit table. The bound before the final table access tests only for an index above 36, so a negative index passes it, as does 36 itself. Perl strings hold code points beyond the Unicode range, and one such code point overflows the accumulation on its own. Valid input wraps it as well, for example 1927 ASCII letters followed by U+10FFFF. The conversion functions encode a label before they check its length, so a long label reaches the encoder through the documented API. Only the XS backend is affected. Encoding an attacker-supplied string copies a byte from outside the digit table into the encoded result or crashes the process.

Overview

State: PUBLISHED
Assigner (CNA): CPANSec
CVSS severity: —
CVSS score: —
CVSS vector: —
Effective score: 6.5 / 10 MEDIUM source: NVD
CWE(s): CWE-190, CWE-125
Reserved: 2026-08-15
Published: 2026-09-22 07:18 UTC
Last updated: 2026-09-22 17:07 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/74xxx/CVE-2026-74765.json

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: 6.5 / 10 MEDIUM source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
NVD CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
Exploitability subscore: 3.9 / 10
Impact subscore: 2.5 / 10
EPSS score: 0.0016 (probability of exploitation in next 30 days)
EPSS percentile: 5.25% vs all CVEs — higher = more likely to be exploited, as of 2026-09-22

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-2026-84289
Assigner: CPANSec
Published: Sep 22, 2026, 7:18:46 AM
Updated: Sep 22, 2026, 5:07:26 PM
EUVD base score (CVSS 3.1): 6.5 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
EUVD-reported EPSS: 0.1600
Aliases: GHSA-xw3q-mp5h-p8jx

ENISA description: Net::IDN::Punycode versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode. The XS backend keeps the punycode delta, and the digit index derived from it, in a signed int. The accumulation `delta += (m-n) * (h+1)` has no overflow check, so a large enough code point wraps the delta and the digit index leaves the range of the 36-entry digit table. The bound before the final table access tests only for an index above 36, so a negative index passes it, as does 36 itself. Perl strings hold code points beyond the Unicode range, and one such code point overflows the accumulation on its own. Valid input wraps it as well, for example 1927 ASCII letters followed by U+10FFFF. The conversion functions encode a label before they check its length, so a long label reaches the encoder through the documented API. Only the XS backend is affected. Encoding an attacker-supplied string copies a byte from outside the digit table into the encoded result or crashes the process.

EUVD references (5)

Affected products (1)

Vendor	Product	Versions	Platforms
—	—	`0` (affected)	—

Vendor references (5)

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 (6)

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/2026/09/22/11 af854a3a-2127-422b-91ae-364da2661108
https://datatracker.ietf.org/doc/html/rfc3492#section-6.4 9b29abf9-4ab0-4765-b253-1875cd9b441e
https://github.com/robrwo/Net-IDN-Encode/commit/27a91ccdb6c9b41f75ba198f5ae154d14e225de2.patch 9b29abf9-4ab0-4765-b253-1875cd9b441e
https://github.com/robrwo/Net-IDN-Encode/commit/81c7f99fe7430bdc5116081508dffdb56f376861.patch 9b29abf9-4ab0-4765-b253-1875cd9b441e
https://github.com/robrwo/Net-IDN-Encode/commit/89d5aa8d3504c5e96061ab76d1541a89c16157cf.patch 9b29abf9-4ab0-4765-b253-1875cd9b441e
https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes 9b29abf9-4ab0-4765-b253-1875cd9b441e

Remediations (10)

July 2026 Critical Patch Update Released | security - Oracle Blogs

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.

2026-09-23 15:45 UTC
Security Update Guide - Microsoft

web:msrc.microsoft.com

The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.

2026-09-23 15:45 UTC
Cisco Advance Notification for Publication of September 16, 2026 ...

web:sec.cloudapps.cisco.com

On September 16, 2026 , the Cisco Product Security Incident Response Team (PSIRT) published the advisories that are listed in the following tables. To remediate these vulnerabilities, Cisco strongly recommends that customers upgrade to the fixed software that is indicated in the advisories. For more information about changes in Cisco PSIRT vulnerability disclosure, see Strengthening the ...

2026-09-23 15:45 UTC
Microsoft Patch Tracker (September 2026): Exploit-Ranked | Senserva

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 15:45 UTC
SAP Security Patch Day - June 2026

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.

2026-09-23 15:45 UTC
SAP Security Patch Day - September 2026

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 8 th of September 2026 , SAP security patch day saw the release of 19 new security notes. There is 1 update to ...

2026-09-23 15:45 UTC
August 2026 CVE Advisory Notification - Security

web:support.servicenow.com

Due to additional analysis provided by the security researcher who discovered CVE - 2026 -6876, we have upgraded the severity rating of CVE - 2026 -6876 from High to Critical. This change affects only the severity

2026-09-23 15:45 UTC
CVE-2026-74765 | Ubuntu

web:ubuntu.com

Description Net::IDN::Punycode versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode. The XS backend keeps the punycode delta, and the digit index derived from it, in a signed int. The accumulation `delta += (m-n) * (h+1)` has no overflow check, so a large enough code point wraps the delta and the digit index leaves the ...

2026-09-23 15:45 UTC
Oracle Critical Patch Update Advisory - July 2026

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.

2026-09-23 15:45 UTC
Oracle Critical Security Patch Update Advisory - May 2026

web:www.oracle.com

This Critical Security Patch Update contains 35 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Security Patch Update and other Oracle Software Security Assurance activities is located at May 2026 Critical Security Patch Update: Executive Summary and Analysis.

2026-09-23 15:45 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-74765.json.

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