---
title: "CVE-2026-87080: Net::IDN::Punycode - Logic Error"
description: "Net::IDN::Punycode::PP before 2.590 for Perl contains a logic error in decode_punycode caused by improper handling of truncated labels in the pure-Perl decoder, letting attackers cause inconsistent name resolution, exploit requires crafted punycode labels."
url: https://panop.io/threat-heartbeat/CVE-2026-87080/
---

# CVE-2026-87080 Net::IDN::Punycode - Logic Error

Net::IDN::Punycode::PP before 2.590 for Perl contains a logic error in decode\_punycode caused by improper handling of truncated labels in the pure-Perl decoder, letting attackers cause inconsistent name resolution, exploit requires crafted punycode labels.

CVSS base score 9.1 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.39% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-87080)

## Details

Type

Logic Error

Impact

Denial Of Service

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Published

22 September 2026

Updated

15 October 2026

Weakness

[CWE-1286](https://cwe.mitre.org/data/definitions/1286.html)

## Vendor fix

Update to version 2.590 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-87080](https://nvd.nist.gov/vuln/detail/CVE-2026-87080)
- [https://github.com/robrwo/Net-IDN-Encode/commit/48436c7ad2c4d4c6398110e11133754fc476a783.patch](https://github.com/robrwo/Net-IDN-Encode/commit/48436c7ad2c4d4c6398110e11133754fc476a783.patch)
- [https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes](https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes)
- [http://www.openwall.com/lists/oss-security/2026/09/22/15](http://www.openwall.com/lists/oss-security/2026/09/22/15)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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