DEBIAN-CVE-2026-39821
- Source
- https://security-tracker.debian.org/tracker/CVE-2026-39821
- Import Source
- https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-39821.json
- JSON Data
- https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-39821
- Upstream
- Published
- 2026-05-22T16:16:20Z
- Modified
- 2026-09-18T08:47:26Z
- 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
Affected packages
Debian:12 / golang-golang-x-net
Package
- Name
- golang-golang-x-net
- Purl
- pkg:deb/debian/golang-golang-x-net?arch=source&distro=bookworm
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affected
Affected versions
1:0.*
1:0.7.0+dfsg-1
1:0.10.0-1
1:0.11.0-1
1:0.14.0-1
1:0.15.0-1
1:0.15.0-2
1:0.17.0+dfsg-1
1:0.19.0+dfsg-1
1:0.20.0+dfsg-1
1:0.21.0+dfsg-1
1:0.22.0+dfsg-1
1:0.23.0+dfsg-1
1:0.24.0+dfsg-1
1:0.25.0+dfsg-1
1:0.26.0+dfsg-1
1:0.26.0+dfsg-2
1:0.27.0-1
1:0.27.0-2
1:0.47.0-1
1:0.47.0-2
1:0.53.0-1
1:0.53.0-2~bpo13+1
1:0.53.0-2
1:0.55.0-1
1:0.56.0-1
1:0.57.0-1
1:0.58.0-1
Debian:13 / golang-golang-x-net
Package
- Name
- golang-golang-x-net
- Purl
- pkg:deb/debian/golang-golang-x-net?arch=source&distro=trixie
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affected
Debian:14 / golang-golang-x-net
Package
- Name
- golang-golang-x-net
- Purl
- pkg:deb/debian/golang-golang-x-net?arch=source&distro=forky