{"id":"RLSA-2026:20589","summary":"Important: dnsmasq security update","details":"The dnsmasq packages contain Dnsmasq, a lightweight DNS (Domain Name Server) forwarder and DHCP (Dynamic Host Configuration Protocol) server.\n\nSecurity Fix(es):\n\n* dnsmasq: dnsmasq: heap buffer overflow in cache via NAME_ESCAPE expansion (CVE-2026-2291)\n\n* dnsmasq: NSEC bitmap parsing infinite loop (CVE-2026-4890)\n\n* dnsmasq: RRSIG rdlen underflow leading to heap OOB read (CVE-2026-4891)\n\n* dnsmasq: DHCPv6 CLID buffer overflow in helper process (CVE-2026-4892)\n\n* dnsmasq: Broken ECS source validation bypass (CVE-2026-4893)\n\nFor more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.","modified":"2026-05-29T00:30:04.780203744Z","published":"2026-05-29T00:00:29.215827Z","upstream":["CVE-2026-2291","CVE-2026-4890","CVE-2026-4891","CVE-2026-4892","CVE-2026-4893"],"references":[{"type":"ADVISORY","url":"https://errata.rockylinux.org/RLSA-2026:20589"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2439088"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2458516"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2458517"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2458518"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2458519"}],"affected":[{"package":{"name":"dnsmasq","ecosystem":"Rocky Linux:8","purl":"pkg:rpm/rocky-linux/dnsmasq?distro=rocky-linux-8&epoch=0"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0:2.79-36.el8_10"}],"database_specific":{"yum_repository":"AppStream"}}],"database_specific":{"source":"https://storage.googleapis.com/resf-osv-data/RLSA-2026:20589.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}],"credits":[{"name":"Rocky Enterprise Software Foundation"},{"name":"Red Hat"}]}