ALPINE-CVE-2026-39821
- Source
- https://security.alpinelinux.org/vuln/CVE-2026-39821
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-39821.json
- JSON Data
- https://api.osv.dev/v1/vulns/ALPINE-CVE-2026-39821
- Upstream
- Published
- 2026-05-22T16:16:20Z
- Modified
- 2026-11-03T06:32:55Z
- Severity
-
- 9.6 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N CVSS Calculator
- Summary
- [none]
- Details
-
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