CVE-2026-87078 Affecting libnet-idn-encode-perl package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DEBIAN14-LIBNETIDNENCODEPERL-20044868
- published22 Sept 2026
- disclosed22 Sept 2026
Introduced: 22 Sep 2026
NewCVE-2026-87078 (opens in a new tab)How to fix?
There is no fixed version for Debian:14 libnet-idn-encode-perl.
NVD Description
Note: Versions mentioned in the description apply only to the upstream libnet-idn-encode-perl package and not the libnet-idn-encode-perl package as distributed by Debian.
See How to fix? for Debian:14 relevant fixed versions and status.
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.
References
- https://security-tracker.debian.org/tracker/CVE-2026-87078
- https://github.com/robrwo/Net-IDN-Encode/commit/92572f726e48af5559de4cc8a831463b79dfb217.patch
- https://github.com/robrwo/Net-IDN-Encode/commit/edad63e0eeeeb18d93bc6dfe4d9dcdff9c244e1b.patch
- https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes
- http://www.openwall.com/lists/oss-security/2026/09/22/13