{"id":"AZL-108671","summary":"CVE-2026-98493 affecting package kernel 6.6.157.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ipconfig: bound DHCP option construction\n\nic_dhcp_init_options() appends the hostname (option 12), vendor-class\n(option 60) and client-ID (option 61) options into the fixed 312-byte\nbootp_pkt.exten[] buffer.  Only the client-ID branch checked the\nremaining space; the hostname and vendor-class writes were unbounded.\n\nA 64-byte hostname together with the maximum 252-byte dhcpclass=\nidentifier needs 18 + (2 + 64) + (2 + 252) = 338 of the 312 available\nbytes even before the terminating END marker, so the vendor-class memcpy\nruns past the end of exten[].  With CONFIG_FORTIFY_SOURCE this is\nreported as a field-spanning write and, when the kernel is booted with\npanic_on_warn=1, aborts boot with a panic.\n\nRoute the optional options through a common helper that makes sure the\noption, its 2-byte header and the END marker all fit and drops an option\nthat would not.  Configurations with short options keep sending exactly\nthe same bytes as before.","modified":"2026-10-20T05:35:13Z","published":"2026-10-18T16:17:00Z","upstream":["CVE-2026-98493"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98493"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.157.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-108671.json"}}],"schema_version":"1.9.0"}