Answer in brief
CVE-2016-15059 records a Critical severity (CVSS 9.8) vulnerability in 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 current sources do not mark it as known exploited. The current feed maps Net-IDN-Encode (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 9.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Net-IDN-Encode (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Net-IDN-Encodegeneric | >=0 <2.301 | 2.301 |
Published upstream
Sep 22, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 22, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 22, 2026
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.
Quoted source text, attributed separately from HOL analysis.