CVE-2016-15059
Net::IDN::Punycode versions before 2.301 for Perl allow a heap buffer overflow via unchecked writes past the output buffer in encode_punycode
- Published
- Updated
- Reserved
- Assigned by
- CPANSec
Description
Net::IDN::Punycode versions before 2.301 for Perl allow a heap buffer overflow via unchecked writes past the output buffer in encode_punycode. The XS backend builds the encoded label in the string buffer of the scalar it returns, sized from the input length. The loop that emits the digits of each code point checks for room before every write, but the write of the last digit of each round and the write of the terminating NUL do not, so an input whose encoded form fills the buffer writes past its end. Only the XS backend is affected. Encoding an attacker-supplied string corrupts the heap.
Timeline
ID reserved
By CPANSec
- 14 days later
· 14 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Deferred | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.42% · top 64% of all CVEs (9 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Weakness
Affected products
Net-IDN-Encode
- affected < 2.301
What to do
Solution: Upgrade to Net-IDN-Encode 2.301 or later.
References (4)
- https://rt.cpan.org/Ticket/Display.html?id=118924 (opens in a new tab)issue-tracking
- https://github.com/robrwo/Net-IDN-Encode/commit/9a3ba07f15d22c0347eefee9625b012cbc803657.patch (opens in a new tab)patch
- https://metacpan.org/release/CFAERBER/Net-IDN-Encode-2.301/changes (opens in a new tab)release-notes
- http://www.openwall.com/lists/oss-security/2026/09/22/10 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2016-15059)Record last updated .