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Flatpak released 1.18.4, with the same fixes in development version 1.19.2, to address high-impact flaws affecting its Linux application sandboxing and distribution framework. The updates prevent malicious applications from abusing privileged operations to overwrite or delete arbitrary host files, including attacks involving empty files or a symlink to /run/host/monitor/resolv.conf. They also stop authenticated OCI repository download tokens from being exposed to other local users, restrict unsafe fields in .desktop and D-Bus .service files, and prevent sandboxed applications from signaling process groups containing host parent processes, an action that could terminate the desktop environment.
Earlier Flatpak 1.18.1 fixes addressed a broader set of symlink and path-traversal weaknesses, including sandbox escape conditions that enabled host filesystem read/write access, root-level arbitrary writes, arbitrary host-file reads, an anti-downgrade bypass, and a 32-bit buffer overflow. CVE assignments were published for the resolved issues, while two remained pending MITRE assignment at the time of the disclosure; a separate identifier, CVE-2026-76925, applies to a RHEL-specific backport issue rather than upstream Flatpak. Organizations should update deployed Flatpak installations to a fixed maintenance or development release and review systems where untrusted Flatpak applications may have run.
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4 events from the most recent confirmed update back to the earliest known activity.
Flatpak released stable version 1.18.4 and development version 1.19.2 with fixes for privileged arbitrary-file overwrites and deletion, OCI authentication-token exposure, unsafe .desktop and D-Bus service-file fields, and sandboxed-app signals that could kill the desktop environment.
Simon McVittie published CVE assignments for the Flatpak vulnerabilities, while noting that the revokefs local-root-escalation issue and the .ld.so symlink issue still had pending MITRE requests. The notice also clarified that CVE-2026-76925 applied to a Red Hat backport and not upstream Flatpak.
Flatpak 1.18.1 addressed multiple vulnerabilities, including sandbox escape, local root privilege escalation, arbitrary host-file reads or writes, an anti-downgrade bypass, and a 32-bit buffer overflow. The fixes included flaws assigned CVE-2026-90616, CVE-2026-96275, CVE-2026-96276, CVE-2026-96279, CVE-2026-92162, CVE-2026-96280, CVE-2026-96281 and CVE-2026-96282, plus two issues awaiting MITRE assignments.
Flatpak 1.16.4 fixed CVE-2026-96284, an arbitrary-read issue affecting files accessible to the flatpak or _flatpak system user, and CVE-2026-96283, which could prevent cancellation of another user's flatpak-system-helper pull.
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Flatpak released **1.16.4** to fix four security issues affecting earlier versions, led by **`CVE-2026-34078`**, a critical flaw in the `flatpak-portal` D-Bus service that can let a malicious sandboxed app escape confinement, access arbitrary host files, and potentially execute code in the host context. The bug stems from acceptance of app-controlled symlinked `sandbox-expose` paths that are resolved and mounted from the host into the sandbox. Flatpak also patched **`CVE-2026-34079`**, which allows arbitrary file deletion on the host through improper validation during `ld.so` cache cleanup, along with a low-severity arbitrary file-read issue in the `flatpak-system-helper` context when a system OCI repository is configured and a cross-user `CancelPull` flaw. The fixes were issued in **Flatpak 1.16.4** and the development branch **1.17.4**, with later **1.16.5** and **1.17.5** releases addressing regressions introduced by the critical patch; the fixes are also slated for **1.18.0**. Multiple Linux distributions, including Debian, Ubuntu, SUSE, RHEL, Gentoo, Arch, and Fedora, were reported as affected or tracking updates, and Debian published a security advisory for Flatpak. Flatpak and downstream advisories urged administrators to upgrade promptly, while temporary mitigation for the sandbox-escape issue included disabling or masking the Flatpak Portal, with the warning that some applications may stop working correctly.
Jun 29, 2026
Canonical disclosed and patched three **snapd** vulnerabilities, led by **CVE-2026-8933**, a high-severity local privilege escalation flaw in **snap-confine** that can let a local user gain **root** on affected Ubuntu Desktop systems. Qualys reported that Ubuntu Desktop 26.04, 25.10, and fully updated 24.04 installations using the file-capabilities configuration for `snap-confine` are exposed because the process retains near-root capabilities while operating with the attacker’s effective UID, allowing attacker-owned files and directories to be created during a race window. The flaw can be exploited through symlink-based arbitrary file creation and permission changes, then by planting a malicious udev rule in an AppArmor-permitted path under `/run/udev/`, which can be triggered to execute attacker-controlled commands as root via `systemd-udevd`. Canonical also addressed **CVE-2026-15226**, a **snap-confine** sandbox confinement bypass caused by missing `setuid` restrictions in seccomp templates, which could let code running inside a strictly confined snap create or manipulate setuid binaries and weaken confinement boundaries. A third issue, **CVE-2024-5300**, involved an AppArmor base profile misconfiguration that could expose hashed passwords through `systemd-userdbd`. Fixes are scheduled in **snapd 2.76.1** and corresponding Ubuntu package updates for Xenial, Bionic, Focal, Jammy, Noble, and Resolute, with Canonical publishing advisory **USN-8579-1**; Qualys said it had a working exploit for CVE-2026-8933 but reported no evidence of active exploitation.
Aug 11, 2026
Apple disclosed two high-severity macOS vulnerabilities, **CVE-2026-28891** and **CVE-2026-28817**, that could allow an application or sandboxed process to escape sandbox restrictions. Both flaws were attributed to race conditions, classified as **CWE-362**, and carried the same `CVSS v3.1` vector: `AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H`, indicating local exploitation with potentially severe impact to confidentiality, integrity, and availability. Apple said the issues were remediated through **additional validation** and **improved state handling**. Fixes were released for **macOS Sequoia 15.7.5**, **macOS Sonoma 14.8.5**, and **macOS Tahoe 26.4**, and organizations running affected macOS systems should prioritize those updates because successful exploitation could let untrusted code break out of the sandbox and operate with broader system access.
Jun 29, 2026