USN-8790-1: Expat vulnerabilities

It was discovered that Expat could be made to allocate large amounts of memory when parsing a small crafted document. An attacker could possibly use this issue to cause Expat to consume resources, leading to a denial of service. This issue was only addressed in Ubuntu 24.04 LTS. (CVE-2025-59375) It was discovered that Expat incorrectly handled empty external parameter entity content. An attacker could possibly use this issue to cause Expat to crash, resulting in a denial of service. (CVE-2026-32776) It was discovered that Expat incorrectly handled certain DTD content. An attacker could possibly use this issue to cause Expat to enter an infinite loop, resulting in a denial of service. (CVE-2026-32777) It was discovered that Expat incorrectly handled memory when retrying after an earlier out-of-memory condition. An attacker could possibly use this issue to cause Expat to crash, resulting in a denial of service. (CVE-2026-32778) It was discovered that Expat performed attribute name collision checks inefficiently. An attacker could possibly use this issue to cause Expat to consume resources when processing a moderately sized crafted XML document, resulting in a denial of service. This issue was only addressed in Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-45186) It was discovered that Expat used insufficient entropy, allowing hash flooding through a crafted XML document. An attacker could possibly use this issue to cause Expat to consume resources, leading to a denial of service. This issue was only addressed in Ubuntu 14.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-41080) It was discovered that Expat did not track handler call depth for certain functions called from within handlers, leading to a use-after-free. An attacker could possibly use this issue to cause Expat to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2026-50219, CVE-2026-56412) It was discovered that Expat incorrectly handled certain values, leading to integer overflows. An attacker could possibly use this issue to cause Expat to crash, resulting in a denial of service. (CVE-2026-56403, CVE-2026-56404, CVE-2026-56405) It was discovered that Expat incorrectly handled certain values, leading to an integer overflow. An attacker could possibly use this issue to cause Expat to crash, resulting in a denial of service. This issue only affected Ubuntu