CVE-2026-100395

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{"affected": [{"affectedData": [{"product": "lxc", "vendor": "lxc", "versions": [{"status": "affected", "version": "<= 7.0.0"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "LXC is a userspace interface for the Linux kernel containment features used to create and manage system containers. In LXC 7.0.0 and earlier, lxc-copy and the public liblxc clone() API can follow attacker-controlled symbolic links while updating /etc/hostname in a copied container root filesystem. The affected surfaces are lxc-copy and liblxc's public lxc_container::clone() API. The privileged cloning process must run as root. The source rootfs must be attacker-controlled or less trusted. A symlink can be placed at etc/hostname or in an intermediate component. The clone operation preserves the symlink before updating the hostname. The vulnerable write truncates and overwrites an existing file outside the destination rootfs. When root clones an untrusted container without LXC_CLONE_KEEPNAME, the copied symlink can resolve outside the destination rootfs and cause the privileged process to overwrite an existing host file with the destination container name. Unprivileged use and managers with independent cloning implementations are not affected. LXC_CLONE_KEEPNAME avoids the hostname update and therefore the affected write."}], "id": "CVE-2026-100395", "lastModified": "2026-11-12T22:18:35.610", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "LOCAL", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.8, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "ACTIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-100395", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-11-09T17:36:00.553409Z", "version": "2.0.3"}}]}, "published": "2026-11-05T22:17:41.803", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/lxc/lxc/commit/6424a91a55efc54edc25ca46e9165bd9f35b50b7"}, {"source": "security-advisories@github.com", "url": "https://github.com/lxc/lxc/commit/fa12709a79c2b63b3918297d7505108fcc840eb6"}, {"source": "security-advisories@github.com", "url": "https://github.com/lxc/lxc/security/advisories/GHSA-r23j-58gg-pjjc"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-59"}, {"lang": "en", "value": "CWE-61"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{"bugzilla": {"description": "lxc: lxc: Arbitrary file overwrite via symbolic link following during container clone operations", "id": "2567564", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2567564"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.1", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H", "status": "draft"}, "cwe": "CWE-59", "details": ["A flaw was found in LXC. When a privileged user or process clones an untrusted container, LXC follows symbolic links (symlinks) while updating the hostname in the target container file system. An attacker with control over the source container can craft a symlink targeting files outside the destination directory. This flaw allows the privileged process to overwrite and truncate arbitrary files on the host, leading to data corruption or a denial of service."], "mitigation": {"lang": "en:us", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability."}, "name": "CVE-2026-100395", "public_date": "2026-11-05T21:45:58Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-100395\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-100395\nhttps://github.com/lxc/lxc/commit/6424a91a55efc54edc25ca46e9165bd9f35b50b7\nhttps://github.com/lxc/lxc/commit/fa12709a79c2b63b3918297d7505108fcc840eb6\nhttps://github.com/lxc/lxc/security/advisories/GHSA-r23j-58gg-pjjc"], "statement": "This vulnerability is rated as Important rather than Moderate because an untrusted container can exploit privileged cloning operations to overwrite arbitrary host files, severely impacting host integrity and availability. Red Hat Enterprise Linux does not provide LXC in its default or supported container runtime stack, deploying Podman and CRI-O instead for container management. In environments where LXC is utilized, exposure is restricted to administrative workflows cloning untrusted source containers without preserving the original container name, while unprivileged cloning operations remain unaffected.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,7.0.0]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "lxc", "source": "cna", "vendor": "lxc"}, "product": "lxc", "vendor": "lxc"}], "created": "2026-11-06T00:00:19.375400+00:00", "updated": "2026-11-06T00:00:21.491790+00:00", "vendors": ["lxc", "lxc$PRODUCT$lxc"]}