CVE-2026-87081 Affecting perl-Net-IDN-Encode package, versions <0:2.590-1.amzn2023.0.1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-AMZN2023-PERLNETIDNENCODE-20856733
- published13 Oct 2026
- disclosed22 Sept 2026
Introduced: 22 Sep 2026
NewCVE-2026-87081 (opens in a new tab)How to fix?
Upgrade Amazon-Linux:2023 perl-Net-IDN-Encode to version 0:2.590-1.amzn2023.0.1 or higher.
This issue was patched in ALAS2023-2026-3190.
NVD Description
Note: Versions mentioned in the description apply only to the upstream perl-Net-IDN-Encode package and not the perl-Net-IDN-Encode package as distributed by Amazon-Linux.
See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.
Net::IDN::UTS46 versions before 2.590 for Perl allow CPU exhaustion via quadratic punycode encoding of an overlong label before the length check in to_ascii.
to_ascii punycode encodes each label and only then applies the 63-byte DNS limit. encode_punycode in both backends follows the sample implementation in RFC 3492, whose outer loop runs once per distinct non-ASCII code point and scans the whole input each round, so a label of distinct non-ASCII characters costs the square of its length before the limit rejects it. Every ASCII conversion in the distribution, including domain_to_ascii and email_to_ascii, goes through to_ascii.
References
- http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-87081
- https://github.com/robrwo/Net-IDN-Encode/commit/5ac3315131264670efcd3a29857b651506dfee8e.patch
- https://github.com/robrwo/Net-IDN-Encode/commit/ea34f812d7dc67f3b211f4d92e74c6a7e24d764a.patch
- https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes
- http://www.openwall.com/lists/oss-security/2026/09/22/16