Vulnerability · Published Jun 23, 2026 · Assigned by mitre
CVE-2026-57053
Medium 4.0
In plain English
A medium-severity security flaw in libidn from GNU. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)4.0Medium
Exploit odds (30 days)0.1%top 96.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
GNU libidn before 1.44 is prone to out-of-bounds reads of uninitialized memory in the ToUnicode APIs because of mishandling in idna_to_unicode_internal. The affected code is not present in libidn2.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libidn | no fix listed | DEBIAN-CVE-2026-57053 |
| Debian:13 | libidn | no fix listed | DEBIAN-CVE-2026-57053 |
| Debian:14 | libidn | 1.44-1 | DEBIAN-CVE-2026-57053 |
| Ubuntu:22.04:LTS | libidn | 1.38-4ubuntu1.1 | UBUNTU-CVE-2026-57053 |
| Ubuntu:22.04:LTS | libidn | 1.38-4ubuntu1.1 | USN-8521-1 |
| Ubuntu:24.04:LTS | libidn | 1.42-1ubuntu0.1 | USN-8521-1 |
| Ubuntu:24.04:LTS | libidn | 1.42-1ubuntu0.1 | UBUNTU-CVE-2026-57053 |
| Ubuntu:25.10 | libidn | no fix listed | UBUNTU-CVE-2026-57053 |
| Ubuntu:26.04:LTS | libidn | 1.43-2ubuntu0.26.04.1 | USN-8521-1 |
| Ubuntu:26.04:LTS | libidn | 1.43-2ubuntu0.26.04.1 | UBUNTU-CVE-2026-57053 |
Affected products (as reported)
Weakness: CWE-1284 · Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L