{"id":"CVE-2026-56114","summary":"dhcpcd Stack Out-of-Bounds Write in dhcp6_makemessage()","details":"dhcpcd through 10.3.2, fixed in commit 2f00c7b, contains a one-byte stack out-of-bounds write vulnerability in dhcp6_makemessage() in src/dhcp6.c that allows unauthenticated same-link attackers to write beyond a fixed local buffer by serializing an oversized RFC6603 OPTION_PD_EXCLUDE option body. Attackers can send a crafted DHCPv6 ADVERTISE message containing an IA_PD IAPREFIX /0 with a valid OPTION_PD_EXCLUDE using an exclude prefix length of /121 through /128 to trigger the out-of-bounds write and potentially corrupt adjacent stack memory.","modified":"2026-07-08T08:12:41.305414952Z","published":"2026-06-23T16:08:10.043Z","database_specific":{"cna_assigner":"VulnCheck","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56114.json","cwe_ids":["CWE-787"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56114.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56114"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/dhcpcd-stack-out-of-bounds-write-in-dhcp6-makemessage"},{"type":"FIX","url":"https://github.com/NetworkConfiguration/dhcpcd/commit/2f00c7bfc408b6582d331932dfa47829c4819029"},{"type":"PACKAGE","url":"https://github.com/NetworkConfiguration/dhcpcd"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/networkconfiguration/dhcpcd","events":[{"introduced":"0"},{"fixed":"2f00c7bfc408b6582d331932dfa47829c4819029"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"last_affected":"10.3.2"}],"source":["CPE_RANGE","REFERENCES"],"cpe":"cpe:2.3:a:dhcpcd_project:dhcpcd:*:*:*:*:*:*:*:*"}}],"versions":["v10.3.2","v10.3.1","v10.3.0","v10.2.4","v10.2.3","v10.2.2","v10.2.1","v10.2.0","v10.1.0","v10.0.10","v10.0.9","v10.0.8","v10.0.7","v10.0.6","v10.0.5","v10.0.4","v10.0.3","v10.0.2","v10.0.1","v10.0.0","v9.4.0","v9.3.4","v9.3.3","v9.3.2","v9.3.1","v9.3.0","v9.2.0","v9.1.4","v9.1.3","v9.1.2","v9.1.1","v9.1.0","v9.0.2","v9.0.1","v9.0.0","v8.1.2","v8.1.1","v8.1.0","v8.0.6","v8.0.5","v8.0.4","v8.0.3","v8.0.2","v8.0.1","v8.0.0","v7.1.1","v7.1.0","v7.0.8","v7.0.7","v7.0.6","v7.0.5b","v7.0.5a","v7.0.5","v7.0.4","v7.0.3","v7.0.2","v7.0.1","v7.0.0","v7.0.0-rc4","v7.0.0-rc3","v7.0.0-rc2","v7.0.0-rc1","v7.0.0-beta3","v7.0.0-beta2","v7.0.0-beta1","v6.11.3","v6.11.2","v6.11.1","v6.11.0","v6.10.3","v6.10.2","v6.10.1","v6.10.0","v6.9.4","v6.9.3","v6.9.2","v6.9.1","v6.9.0","v6.8.2","v6.8.1","v6.8.0","v6.7.1","v6.7.0","v6.6.7","v6.6.6","v6.6.5","v6.6.4","v6.6.3","v6.6.2","v6.6.1","v6.6.0","v6.5.1","v6.5.0","v6.4.7","v6.4.6","v6.4.5","v6.4.4","v6.4.3","v6.4.2","v6.4.1","v6.4.0","v6.3.2","v6.3.1","v6.3.0","v6.2.1","v6.2.0","v5.5.6","v6.1.0","v6.0.5","v6.0.4","v6.0.3","v6.0.2","v6.0.1","v6.0.0","v5.99.7","v5.99.6","v5.99.3","v5.6.2","v5.6.1","v5.6.0","v5.5.5","v5.5.4","v5.5.3","v5.5.2","v5.5.1","v5.5.0","v5.2.12","v5.2.11","v5.2.10","v5.2.9","v5.2.7","v5.2.6","v5.2.4","v5.2.3","v5.2.2","v5.2.1","v5.2.0","v5.1.5","v5.1.4","v5.1.3","v5.1.2","v5.1.1","v5.1.0","v5.0.6","v5.0.5","v5.0.4","v5.0.3","v5.0.2","v5.0.1","v3.2.3"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-56114.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"}]}