Ubuntu 26.04 LTS GNU C Library Critical Denial of Service USN-8611

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Several security issues were fixed in GNU C Library. Software Description: - glibc: GNU C Library Details: It was discovered that the GNU C Library iconv function incorrectly handled certain IBM character sets. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-4046) It was discovered that the GNU C Library DNS functions incorrectly handled certain DNS server responses when using gethostbyaddr or gethostbyaddr_r. An attacker in a privileged network position could possibly use this issue to cause an application to violate DNS specification or obtain incorrect hostname information. This issue only affected Ubuntu 24.04 LTS. (CVE-2026-4437, CVE-2026-4438) It was discovered that the GNU C Library deprecated debugging functions incorrectly enforced caller-supplied buffer lengths. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. (CVE-2026-5435) It was discovered that the GNU C Library scanf family of fu... Read the Full Advisory

Several security issues were fixed in GNU C Library.

Software Description:

- glibc: GNU C Library

It was discovered that the GNU C Library iconv function incorrectly handled

certain IBM character sets. An attacker could possibly use this issue to

cause a denial of service. (CVE-2026-4046)

It was discovered that the GNU C Library DNS functions incorrectly handled

certain DNS server responses when using gethostbyaddr or gethostbyaddr_r.

An attacker in a privileged network position could possibly use this issue

to cause an application to violate DNS specification or obtain incorrect

hostname information. This issue only affected Ubuntu 24.04 LTS.

(CVE-2026-4437, CVE-2026-4438)

It was discovered that the GNU C Library deprecated debugging functions

incorrectly enforced caller-supplied buffer lengths. An attacker could

possibly use this issue to cause a denial of service or execute arbitrary

code. (CVE-2026-5435)

It was discovered that the GNU C Library scanf family of fu...

The problem can be corrected by updating your system to the following package versions: Ubuntu 26.04 LTS libc6 2.43-2ubuntu2.3 Ubuntu 24.04 LTS libc6 2.39-0ubuntu8.8 Ubuntu 22.04 LTS libc6 2.35-0ubuntu3.14 After a standard system update you need to reboot your computer to make all the necessary changes.

CVE-2026-4046, CVE-2026-4437, CVE-2026-4438, CVE-2026-5435,

CVE-2026-5450, CVE-2026-5928, CVE-2026-6238

Ubuntu Security Notice USN-8611-1

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