CVE-2026-87078 Net::IDN::Punycode - Denial of Service

Net::IDN::Punycode versions >= 2.302 and < 2.590 for Perl contain a memory leak caused by improper buffer release in decode_punycode XS backend, letting attackers cause memory exhaustion by sending invalid labels, exploit requires attacker to supply invalid 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 ↗

Details

Type
Denial of Service
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-401

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

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