{"id":"CVE-2026-90616","title":"In Flatpak before 1.18.1, a malicious sandboxed app can obtain arbitrary read and write access to files on the host, which can be escalated to arbitrary code execution on the host, a different vulnerability than CVE-2026-76925","summary":"In Flatpak before 1.18.1, a malicious sandboxed app can obtain arbitrary read and write access to files on the host, which can be escalated to arbitrary code execution on the host, a different vulnerability than CVE-2026-76925. Flatpak c…","severity":"high","cvss":7.4,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-61","CWE-59"],"vendor":"Flatpak","product":"Flatpak","affected":["Flatpak < 1.18.1"],"published":"2026-09-12","updated":"2026-09-22","sourceUpdated":"2026-09-22T19:56:19.073","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90616","references":[{"url":"https://github.com/flatpak/flatpak/security/advisories/GHSA-8688-9x26-hhxj","label":"cve@mitre.org"},{"url":"https://www.openwall.com/lists/oss-security/2026/08/11/9","label":"cve@mitre.org"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90616.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-90616"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532613"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-90616"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90616"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00167,"epssPercentile":0.0635,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-09-14T18:22:12.062132Z"},"scores":{"nvd":7.4,"cna":7.4,"vendor":7.8},"ingestedAt":"2026-09-14T15:23:07.478Z","slug":"CVE-2026-90616","body":"## Overview\n\nIn Flatpak before 1.18.1, a malicious sandboxed app can obtain arbitrary read and write access to files on the host, which can be escalated to arbitrary code execution on the host, a different vulnerability than CVE-2026-76925. Flatpak creates a few app data directories (e.g., /var/cache, /var/data, /var/config, and /var/tmp) in every sandbox on every app launch where, in some cases, components of the path are attacker-controlled. Missing symlink protection can redirect the directories. Some of these directories are bind-mounted by Flatpak by passing the path (e.g., /home/user/.var/app/APP_ID/cache/tmp), which contains attacker-controlled directories (tmp) to bwrap --bind SRC DST. bwrap passes the path on to the kernel, which then follows symlinks. A malicious symlink can point to arbitrary locations on the host and it will become mounted inside the sandbox.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90616.json)","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":40.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":203176,"id":"CVE-2026-90616","ts":1789413242946,"field":"cvss","old":"7.8","new":"7.4"},{"seq":202808,"id":"CVE-2026-90616","ts":1789403724999,"field":"cvss","old":"7.4","new":"7.8"}]}