{ "document": { "aggregate_severity": { "namespace": "https://access.redhat.com/security/updates/classification/", "text": "Moderate" }, "category": "csaf_vex", "csaf_version": "2.0", "distribution": { "text": "Copyright © Red Hat, Inc. All rights reserved.", "tlp": { "label": "WHITE", "url": "https://www.first.org/tlp/" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original.", "title": "Terms of Use" } ], "publisher": { "category": "vendor", "contact_details": "https://access.redhat.com/security/team/contact/", "issuing_authority": "Red Hat Product Security is responsible for vulnerability handling across all Red Hat products and services.", "name": "Red Hat Product Security", "namespace": "https://www.redhat.com" }, "references": [ { "category": "self", "summary": "Canonical URL", "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-56114.json" } ], "title": "dhcpcd: dhcpcd: Denial of Service due to stack out-of-bounds write via crafted DHCPv6 message", "tracking": { "current_release_date": "2026-07-14T22:05:53+00:00", "generator": { "date": "2026-07-14T22:05:53+00:00", "engine": { "name": "Red Hat SDEngine", "version": "5.3.2" } }, "id": "CVE-2026-56114", "initial_release_date": "2026-06-23T16:08:10.043000+00:00", "revision_history": [ { "date": "2026-06-23T16:08:10.043000+00:00", "number": "1", "summary": "Initial version" }, { "date": "2026-06-29T19:11:37+00:00", "number": "2", "summary": "Current version" }, { "date": "2026-07-14T22:05:53+00:00", "number": "3", "summary": "Last generated version" } ], "status": "final", "version": "3" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_name", "name": "Red Hat Enterprise Linux 10", "product": { "name": "Red Hat Enterprise Linux 10", "product_id": "red_hat_enterprise_linux_10", "product_identification_helper": { "cpe": "cpe:/o:redhat:enterprise_linux:10" } } } ], "category": "product_family", "name": "Red Hat Enterprise Linux 10" }, { "category": "product_version", "name": "dhcpcd.src", "product": { "name": "dhcpcd.src", "product_id": "dhcpcd.src", "product_identification_helper": { "purl": "pkg:rpm/redhat/dhcpcd?arch=src" } } } ], "category": "vendor", "name": "Red Hat" } ], "relationships": [ { "category": "default_component_of", "full_product_name": { "name": "dhcpcd.src as a component of Red Hat Enterprise Linux 10", "product_id": "red_hat_enterprise_linux_10:dhcpcd.src" }, "product_reference": "dhcpcd.src", "relates_to_product_reference": "red_hat_enterprise_linux_10" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-56114", "cwe": { "id": "CWE-787", "name": "Out-of-bounds Write" }, "discovery_date": "2026-06-23T17:05:07.063469+00:00", "ids": [ { "system_name": "Red Hat Bugzilla ID", "text": "2491842" } ], "notes": [ { "category": "description", "text": "A flaw was found in dhcpcd. An unauthenticated attacker on the same network link could exploit a one-byte stack out-of-bounds write vulnerability in the `dhcp6_makemessage()` function. By sending a specially crafted DHCPv6 ADVERTISE message with an oversized option, the attacker can write beyond a buffer, potentially corrupting adjacent memory. This could lead to a denial of service.", "title": "Vulnerability description" }, { "category": "summary", "text": "dhcpcd: dhcpcd: Denial of Service due to stack out-of-bounds write via crafted DHCPv6 message", "title": "Vulnerability summary" }, { "category": "general", "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.", "title": "CVSS score applicability" } ], "product_status": { "known_affected": [ "red_hat_enterprise_linux_10:dhcpcd.src" ] }, "references": [ { "category": "self", "summary": "Canonical URL", "url": "https://access.redhat.com/security/cve/CVE-2026-56114" }, { "category": "external", "summary": "RHBZ#2491842", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2491842" }, { "category": "external", "summary": "https://www.cve.org/CVERecord?id=CVE-2026-56114", "url": "https://www.cve.org/CVERecord?id=CVE-2026-56114" }, { "category": "external", "summary": "https://nvd.nist.gov/vuln/detail/CVE-2026-56114", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-56114" }, { "category": "external", "summary": "https://github.com/NetworkConfiguration/dhcpcd/commit/2f00c7bfc408b6582d331932dfa47829c4819029", "url": "https://github.com/NetworkConfiguration/dhcpcd/commit/2f00c7bfc408b6582d331932dfa47829c4819029" }, { "category": "external", "summary": "https://www.vulncheck.com/advisories/dhcpcd-stack-out-of-bounds-write-in-dhcp6-makemessage", "url": "https://www.vulncheck.com/advisories/dhcpcd-stack-out-of-bounds-write-in-dhcp6-makemessage" } ], "release_date": "2026-06-23T16:08:10.043000+00:00", "remediations": [ { "category": "workaround", "details": "To mitigate this issue, restrict network access to systems running dhcpcd to trusted networks only. If DHCPv6 is not required, it can be disabled by configuring dhcpcd to ignore IPv6 or by disabling IPv6 on the network interfaces. Consult your system's network configuration documentation for specific instructions on disabling DHCPv6 for dhcpcd or network interfaces. A service restart may be required for changes to take effect.", "product_ids": [ "red_hat_enterprise_linux_10:dhcpcd.src" ] }, { "category": "none_available", "details": "Fix deferred", "product_ids": [ "red_hat_enterprise_linux_10:dhcpcd.src" ] } ], "scores": [ { "cvss_v3": { "attackComplexity": "HIGH", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "HIGH", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1" }, "products": [ "red_hat_enterprise_linux_10:dhcpcd.src" ] } ], "threats": [ { "category": "impact", "details": "Moderate", "product_ids": [ "red_hat_enterprise_linux_10:dhcpcd.src" ] } ], "title": "dhcpcd: dhcpcd: Denial of Service due to stack out-of-bounds write via crafted DHCPv6 message" } ] }