CVE-2026-87081
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
Description
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.
INFO
Published Date :
Sept. 22, 2026, 8:16 a.m.
Last Modified :
Sept. 22, 2026, 8:16 a.m.
Remotely Exploit :
No
Source :
9b29abf9-4ab0-4765-b253-1875cd9b441e
Affected Products
The following products are affected by CVE-2026-87081
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update Net::IDN::UTS46 to version 2.590 or later.
- Apply vendor patches if available.
- Monitor system resource usage.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-87081.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-87081 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-87081
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-87081 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-87081 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 9b29abf9-4ab0-4765-b253-1875cd9b441e
Sep. 22, 2026
Action Type Old Value New Value Added Description 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. Added CWE CWE-407 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/87xxx/CVE-2026-87081.json">CVE-2026-87081</a> Added Reference https://github.com/robrwo/Net-IDN-Encode/commit/5ac3315131264670efcd3a29857b651506dfee8e.patch Added Reference https://github.com/robrwo/Net-IDN-Encode/commit/ea34f812d7dc67f3b211f4d92e74c6a7e24d764a.patch Added Reference https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes