CVE-2026-74766

Source
https://cve.org/CVERecord?id=CVE-2026-74766
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74766.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-74766
Downstream
Published
2026-09-22T07:19:09Z
Modified
2026-09-24T03:45:56Z
Severity
  • 8.4 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
Net::IDN::Punycode versions from 2.301 before 2.590 for Perl allow a heap use-after-free via a decoded code point that reallocates the output buffer in decode_punycode
Details

Net::IDN::Punycode versions from 2.301 before 2.590 for Perl allow a heap use-after-free via a decoded code point that reallocates the output buffer in decode_punycode.

The XS backend inserts each decoded code point into the string buffer of the scalar it returns. decode_punycode computes the insertion pointer first and only then grows the buffer when the code point does not fit. The growth reallocates the buffer and updates every pointer except the insertion pointer, so the move that follows and the write of the code point go through a freed pointer. The buffer starts at twice the label length, and a code point above U+FFFF takes four bytes in the output, so a label of such code points outgrows it and forces the reallocation.

Version 2.301, the fix for CVE-2016-15059, introduced the defect. Only the XS backend is affected.

Decoding an attacker-supplied punycode label reads and writes freed heap memory.

Database specific
{
    "cna_assigner":  "CPANSec",
    "cwe_ids":  [
        "CWE-416"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74766.json"
}
References

Affected packages

Git / github.com/robrwo/net-idn-encode

Affected ranges

Type
GIT
Repo
https://github.com/robrwo/net-idn-encode
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
Fixed
Fixed
Database specific
Show details
{
    "extracted_events":  [
        {
            "introduced":  "2.301"
        },
        {
            "fixed":  "2.590"
        }
    ],
    "source":  [
        "DESCRIPTION",
        "REFERENCES"
    ]
}

Affected versions

Net-IDN-Encode-0.*
Net-IDN-Encode-0.999_20100110
Net-IDN-Encode-0.99_20080914
Net-IDN-Encode-0.99_20080919
Net-IDN-Encode-0.99_20091216
Net-IDN-Encode-0.99_20091231
Net-IDN-Encode-1.*
Net-IDN-Encode-1.000
Net-IDN-Encode-1.999_20120107
Net-IDN-Encode-1.999_20120108
Net-IDN-Encode-2.*
Net-IDN-Encode-2.000
Net-IDN-Encode-2.000_20120110
Net-IDN-Encode-2.001
Net-IDN-Encode-2.002
Net-IDN-Encode-2.003
Net-IDN-Encode-2.003_2013122700
Net-IDN-Encode-2.003_2013122701
Net-IDN-Encode-2.003_2013880700
Net-IDN-Encode-2.003_2013881000
Net-IDN-Encode-2.005
Net-IDN-Encode-2.099_20131225
Net-IDN-Encode-2.099_20131226
Net-IDN-tools-0.*
Net-IDN-tools-0.99_20070912
v2.*
v2.501
v2.502

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74766.json"