USN-9065-1: GNU C Library vulnerabilities
It was discovered that the GNU C Library incorrectly handled the ccs= option in the fopen function. An attacker could possibly use this issue to cause GNU C Library to crash or execute arbitrary code. (CVE-2026-18374) It was discovered that the GNU C Library incorrectly handled long domain names in DNS search lists. An attacker on the local network could possibly use this issue to cause GNU C Library to crash, resulting in a denial of service. (CVE-2026-8674) It was discovered that the GNU C Library dynamic loader had a time-of-check to time-of-use race condition when handling the $ORIGIN path expansion in setuid or setgid programs. A local attacker could possibly use this issue to execute arbitrary code with elevated privileges. (CVE-2026-86805) It was discovered that the GNU C Library dynamic loader incorrectly handled $ORIGIN path expansion, leading to a stack-based buffer overflow. A local attacker could possibly use this issue to cause GNU C Library to crash, resulting in a denial of service, or obtain sensitive information. (CVE-2026-95818) It was discovered that the GNU C Library nscd service incorrectly handled large DNS responses. An attacker could possibly use this issue to cause nscd to crash, resulting in a denial of service. (CVE-2026-89092) It was discovered that the GNU C Library strncasecmp function optimized for the Power8 architecture incorrectly handled certain inputs. An attacker could possibly use this issue to cause GNU C Library to crash, resulting in a denial of service. (CVE-2026-97399) It was discovered that the GNU C Library incorrectly restricted path traversal when processing the LANGUAGE environment variable in gettext. A local attacker could possibly use this issue to load message catalogs from arbitrary locations and execute arbitrary code. (CVE-2026-84243)
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
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ubuntu/libc6to a version that resolves this vulnerability.Fixed in 2.44-1ubuntu2.1 - Upgrade
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ubuntu/libc6to a version that resolves this vulnerability.Fixed in 2.43-2ubuntu2.7 - Upgrade
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ubuntu/libc6to a version that resolves this vulnerability.Fixed in 2.39-0ubuntu8.12 - Upgrade
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ubuntu/libc6to a version that resolves this vulnerability.Fixed in 2.35-0ubuntu3.18 - Upgrade
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GNU C Libraryto a version that resolves this vulnerability.Patch USN-9065-1
Event History
Child vulnerabilities
Contains the following vulnerabilities.
Frequently Asked Questions
Which issues described here require an attacker to have local access?
CVE-2026-86805 and CVE-2026-95818 are described as locally exploitable. CVE-2026-86805 could allow elevated-privilege code execution in setuid or setgid programs, while CVE-2026-95818 could cause a crash or disclose sensitive information.
Is any issue exploitable by an attacker on the local network?
Yes. CVE-2026-8674 involves long domain names in DNS search lists and could be used by an attacker on the local network to crash GNU C Library, causing denial of service.
Which issue has the most severe stated impact?
CVE-2026-18374 could cause GNU C Library to crash or allow arbitrary code execution. CVE-2026-86805 could allow a local attacker to execute arbitrary code with elevated privileges.