Import Source
https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-87266.json
JSON Data
https://api.osv.dev/v1/vulns/AZL-87266
Upstream
Published
2026-05-22T16:16:20Z
Modified
2026-08-30T05:24:52Z
Summary
CVE-2026-39821 affecting package kata-containers-preview 3.27.0~preview2-1
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

Affected packages

Azure Linux:3 / kata-containers-preview

Package

Name
kata-containers-preview
Purl
pkg:rpm/azure-linux/kata-containers-preview

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Last affected
3.27.0~preview2-1

Database specific

source
"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-87266.json"