UBUNTU-CVE-2026-39821

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode"xn--example-.com" incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna...

CVE-2026-39821

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode"xn--example-.com" incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna...

CVE-2026-39821

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode"xn--example-.com" incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna...

libidn2 -- roundtrip check vulnerability

CVE list: GNU libidn2 before 2.2.0 fails to perform the roundtrip checks specified in RFC3490 Section 4.2 when converting A-labels to U-labels. This makes it possible in some circumstances for one domain to impersonate another. By creating a malicious domain that matches a target domain except fo...