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 package. For example, a program which performs privilege checks on the ASCII hostname may reject "example.com" but permit "xn--example-.com". If that program subsequently converts the ASCII hostname to Unicode, it will inadvertently permits access to the Unicode name "example.com".
References
Configurations
History
No history.
Information
Published : 2026-05-22 16:16
Updated : 2026-09-15 12:17
NVD link : CVE-2026-39821
Mitre link : CVE-2026-39821
CVE.ORG link : CVE-2026-39821
JSON object : View
Products Affected
golang
- net
CWE
CWE-1289
Improper Validation of Unsafe Equivalence in Input