CVE-2026-96808

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-96808", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "state": "PUBLISHED", "assignerShortName": "mitre", "dateReserved": "2026-09-23T16:58:36.801Z", "datePublished": "2026-09-23T16:58:37.139Z", "dateUpdated": "2026-09-23T18:22:46.208Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "platforms": ["Linux"], "product": "Flatpak", "programFiles": ["revokefs/writer.c"], "repo": "https://github.com/flatpak/flatpak", "vendor": "Flatpak", "versions": [{"lessThan": "1.18.1", "status": "affected", "version": "0", "versionType": "semver"}]}], "descriptions": [{"lang": "en", "value": "In Flatpak before 1.18.1, the revokefs writer, used by the flatpak-system-helper to receive repository data from unprivileged callers, validated file paths by rejecting literal .. components but did not prevent symlink traversal. A malicious local user in an active local session could obtain two revokefs sessions via the system helper, create a symlink in one session pointing into the other session's directory, and retain a file descriptor through that symlink. This allowed the attacker to modify files belonging to a different revokefs session after they had been validated and imported by the system helper. 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{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-96808", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "state": "PUBLISHED", "assignerShortName": "mitre", "dateReserved": "2026-09-23T16:58:36.801Z", "datePublished": "2026-09-23T16:58:37.139Z", "dateUpdated": "2026-09-23T18:22:46.208Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "platforms": ["Linux"], "product": "Flatpak", "programFiles": ["revokefs/writer.c"], "repo": "https://github.com/flatpak/flatpak", "vendor": "Flatpak", "versions": [{"lessThan": "1.18.1", "status": "affected", "version": "0", "versionType": "semver"}]}], "descriptions": [{"lang": "en", "value": "In Flatpak before 1.18.1, the revokefs writer, used by the flatpak-system-helper to receive repository data from unprivileged callers, validated file paths by rejecting literal .. components but did not prevent symlink traversal. A malicious local user in an active local session could obtain two revokefs sessions via the system helper, create a symlink in one session pointing into the other session's directory, and retain a file descriptor through that symlink. This allowed the attacker to modify files belonging to a different revokefs session after they had been validated and imported by the system helper. 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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "platforms": ["Linux"], "product": "Flatpak", "programFiles": ["revokefs/writer.c"], "repo": "https://github.com/flatpak/flatpak", "vendor": "Flatpak", "versions": [{"lessThan": "1.18.1", "status": "affected", "version": "0", "versionType": "semver"}]}], "source": "cve@mitre.org"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In Flatpak before 1.18.1, the revokefs writer, used by the flatpak-system-helper to receive repository data from unprivileged callers, validated file paths by rejecting literal .. components but did not prevent symlink traversal. A malicious local user in an active local session could obtain two revokefs sessions via the system helper, create a symlink in one session pointing into the other session's directory, and retain a file descriptor through that symlink. This allowed the attacker to modify files belonging to a different revokefs session after they had been validated and imported by the system helper. In particular, an attacker could use this to tamper with ostree commit objects in the system repository after they passed signature verification, enabling root-controlled file writes to attacker-chosen paths and local root privilege escalation."}], "id": "CVE-2026-96808", "lastModified": "2026-09-24T21:00:46.893", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.4, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.4, "impactScore": 5.9, "source": "cve@mitre.org", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-96808", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-09-23T18:22:36.969505Z", "version": "2.0.3"}}]}, "published": "2026-09-23T17:17:25.860", "references": [{"source": "cve@mitre.org", "url": "https://github.com/flatpak/flatpak/security/advisories/GHSA-qrwq-7qwx-q9rp"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-61"}], "source": "cve@mitre.org", "type": "Secondary"}]}

{"bugzilla": {"description": "flatpak: Flatpak: Local privilege escalation via symlink traversal in revokefs writer", "id": "2539569", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2539569"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.8", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-59", "details": ["A flaw was found in Flatpak. A malicious local user in an active local session could exploit a symlink traversal vulnerability in the `revokefs` writer. This flaw allows an attacker to modify files belonging to a different `revokefs` session after they have been validated. Consequently, an attacker could tamper with `ostree` commit objects, leading to root-controlled file writes and local root privilege escalation."], "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-2026-96808", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "flatpak", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "flatpak", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "flatpak", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "flatpak", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-09-23T16:58:37Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-96808\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-96808\nhttps://github.com/flatpak/flatpak/security/advisories/GHSA-qrwq-7qwx-q9rp"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": ["linux"], "status": "affected", "versions": {"scheme": "semver", "value": "[0,1.18.1)"}}], "enrichment": {"confidence": 95.0, "confidence_source": "inferred", "scores": [{"score": 95.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Flatpak", "source": "cna", "vendor": "Flatpak"}, "product": "flatpak", "vendor": "flatpak"}], "created": "2026-09-23T18:45:07.144981+00:00", "updated": "2026-09-24T02:30:13.846817+00:00", "vendors": ["flatpak", "flatpak$PRODUCT$flatpak"]}