CVE-2026-87078
UnknownSummary
Net::IDN::Punycode versions from 2.302 before 2.590 for Perl leak the output buffer on every rejected label in decode_punycode. No label length limit exists in the to-Unicode direction, allowing memory growth.
Risk Assessment
An attacker can repeatedly send invalid labels to gradually increase memory usage, eventually exhausting resources or causing service failure.
Recommendation
Update Net::IDN::Punycode to version 2.590 or later. Monitor memory usage in domain name processing applications.
Other vulnerabilities in Net::IDN::Punycode
See all- CVE-2026-87082Unknown
Net::IDN::Punycode versions before 2.590 for Perl do not validate UTF-8 input in encode_punycode. A flagged string with malformed bytes can hang, crash, or return a wrong label. Only direct calls to encode_punycode are affected; the decoder is not vulnerable.
- CVE-2026-87079Unknown
Net::IDN::Punycode versions before 2.590 for Perl allow CPU exhaustion via quadratic insertion cost when decoding long labels in decode_punycode. No label length limit exists in the to-Unicode direction, enabling CPU exhaustion attacks.
- CVE-2026-74766Unknown
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. Decoding an attacker-supplied punycode label reads and writes freed heap memory.
- CVE-2026-74765Unknown
Net::IDN::Punycode versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode. Large code points can cause the digit index to leave the range of the digit table, leading to memory corruption or crash.
- CVE-2016-15059Unknown
Net::IDN::Punycode versions before 2.301 for Perl allow a heap buffer overflow via unchecked writes past the output buffer in encode_punycode. Some digit writes and the terminating NUL write do not check for room, leading to out-of-bounds writes.
Original NVD description (English source)
Net::IDN::Punycode versions from 2.302 before 2.590 for Perl leak the output buffer on every rejected label in decode_punycode. The XS backend allocates the scalar it returns before it validates the input, sizing the buffer at twice the input length. The scalar is released only on the success path, so each of the three croaks that reject a label leaves the scalar and its buffer allocated. Nothing bounds the label length in the to-Unicode direction, since the 63-byte DNS limit is checked only when converting to ASCII. Only the XS backend is affected. A sender who supplies invalid labels grows the process by twice the label length per rejected call, with no successful call needed.

