DEBIAN-CVE-2026-74766

Source
https://security-tracker.debian.org/tracker/CVE-2026-74766
Import Source
https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-74766.json
JSON Data
https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-74766
Upstream
Published
2026-09-22T08:16:40Z
Modified
2026-09-23T05:01:13Z
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
[none]
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.

References

Affected packages

Debian:12 / libnet-idn-encode-perl

Package

Name
libnet-idn-encode-perl
Purl
pkg:deb/debian/libnet-idn-encode-perl?arch=source&distro=bookworm

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.500-3
2.500-5

Ecosystem specific

{
    "urgency":  "not yet assigned"
}

Database specific

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

Debian:13 / libnet-idn-encode-perl

Package

Name
libnet-idn-encode-perl
Purl
pkg:deb/debian/libnet-idn-encode-perl?arch=source&distro=trixie

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.500-5

Ecosystem specific

{
    "urgency":  "not yet assigned"
}

Database specific

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

Debian:14 / libnet-idn-encode-perl

Package

Name
libnet-idn-encode-perl
Purl
pkg:deb/debian/libnet-idn-encode-perl?arch=source&distro=forky

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.500-5

Ecosystem specific

{
    "urgency":  "not yet assigned"
}

Database specific

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