CVE-2026-96280

Flatpak: flatpak: buffer overflow in oci delta stream path names on 32-bit systems

The OCI delta stream parser read sizes as guint64 but passed them to GLib I/O and allocation functions expecting gsize (32 bits on 32-bit systems), causing undersized allocations while subsequent operations use the original 64-bit size, leading to heap buffer overflows. An attacker controlling an OCI registry can craft a delta stream that triggers this during flatpak install/update, potentially achieving code execution on 32-bit systems.

CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed

Vendors

Flatpak Redhat

Products

Flatpak Enterprise Linux Enterprise Linux Eus and 6 more

CVE-2026-96275

Flatpak: flatpak: arbitrary write access as root via extra-data extraction

A malicious or compromised Flatpak repository can write attacker-controlled content to arbitrary locations on the host filesystem via extract_extra_data(). On system installs, the write happens as root. Two issues combine: `files/extra` is resolved via path operations that follow symlinks, and blob names from `xa.extra-data-sources` are not sanitized against `..` traversal.

CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed

Vendors

Flatpak Redhat

Products

Flatpak Enterprise Linux Enterprise Linux Eus and 6 more

CVE-2026-97024

Flatpak: flatpak: arbitrary write in root context via path traversal in deploy directory files/etc

A path traversal vulnerability in Flatpak's handling of the files/etc directory during app deployment allows a malicious Flatpak app to cause certain host system files (such as passwd, group, machine-id, or resolv.conf) to be emptied or replaced with a symlink when the app is installed or upgraded. In system-wide installations, the write is performed as root.

CVSS 3.1 · 7.1 High EPSS < 1% KEV · Not listed

Vendors

Flatpak Redhat

Products

Flatpak Enterprise Linux Enterprise Linux Eus and 3 more

CVE-2026-97023

Flatpak: flatpak: arbitrary file deletion in root context via path traversal in deploy directory export/bin

A path traversal vulnerability in Flatpak's handling of the export/bin directory during app deployment allows a malicious Flatpak app to cause deletion of attacker-chosen files outside the deployment directory when the app is installed or upgraded. In system-wide installations, the deletion is performed as root.

CVSS 3.1 · 7.1 High EPSS < 1% KEV · Not listed

Vendors

Flatpak Redhat

Products

Flatpak Enterprise Linux Enterprise Linux Eus and 3 more

CVE-2026-97027

Flatpak: flatpak: denial of service via unsanitized keys in exported desktop entry / d-bus service files

Flatpak passes through arbitrary vendor-extension keys unmodified when exporting an application's Desktop Entry (.desktop) and D-Bus Service (.service) files, instead of validating against an allowlist. A malicious Flatpak app can use this to cause denial of service (e.g. forced application restart loops) or to influence host D-Bus/systemd activation behavior beyond what the sandbox is intended to permit.

CVSS 3.1 · 3.6 Low EPSS < 1% KEV · Not listed

Vendors

Flatpak Redhat

Products

Flatpak Enterprise Linux Rhel Els

CVE-2026-97026

Flatpak: flatpak: world-writable temporary child repositories in system-helper cache path

Flatpak creates temporary child repository directories under the user cache with world-writable permissions (0777). On multi-user systems with a permissive umask, other local users could read or modify the temporary directory used while installing apps or runtimes, potentially causing installation failures (denial of service); tampered content would fail signature/digest verification rather than being trusted.

CVSS 3.1 · 3.9 Low EPSS < 1% KEV · Not listed

Vendors

Flatpak Redhat

Products

Flatpak Enterprise Linux Rhel Els

CVE-2026-97025

Flatpak: flatpak: world-readable oci authentication token in system-helper cache path

Flatpak writes the OCI repository authentication token with world-readable permissions (0644) in the system-helper's cache directory, allowing other local users on a multi-user system to read the token and impersonate the authenticated user against the OCI repository. Only OCI-based sources (e.g. as used by Fedora) are affected; libostree-based sources such as Flathub are not.

CVSS 3.1 · 3.2 Low EPSS < 1% KEV · Not listed

Vendors

Flatpak Redhat

Products

Flatpak Enterprise Linux Rhel Els

CVE-2026-96284

Flatpak: flatpak: arbitrary read-access to files in the system-helper context via oci symlink following

A malicious user can get read-access to files in the flatpak-system-helper context if a system OCI repository is configured, because the OCI code paths in the system helper follow symlinks when importing OCI images that are under the user's control.

CVSS 3.1 · 2.5 Low EPSS < 1% KEV · Not listed

Vendors

Flatpak Redhat

Products

Flatpak Enterprise Linux Rhel Els

CVE-2026-96283

Flatpak: flatpak: flatpak-system-helper cross-user cancelpull orphans another user's ongoing pull

By calling org.freedesktop.Flatpak.SystemHelper.CancelPull on another user's pull, the pull is not actually cancelled but removed from internal tracking, making it impossible for the owning user to stop it. Ongoing pulls cannot be stopped.

CVSS 3.1 · 3.3 Low EPSS < 1% KEV · Not listed

Vendors

Flatpak Redhat

Products

Flatpak Enterprise Linux Rhel Els

CVE-2026-96282

Flatpak: flatpak: extension metadata path traversal file existence oracle

A malicious Flatpak extension can probe the host filesystem to determine what files and directories exist at arbitrary paths, and host directory listings can be disclosed to sandboxed applications using the extension. Additionally, unvalidated extension metadata can cause extension content to be mounted at unintended locations inside the sandbox.

CVSS 3.1 · 3.1 Low EPSS < 1% KEV · Not listed

Vendors

Flatpak Redhat

Products

Flatpak Enterprise Linux Rhel Els

CVE-2026-97029

Flatpak: flatpak: sandboxed app can signal unsandboxed processes in the same process group

Flatpak's process ID namespace separation does not prevent a sandboxed app's kill(0, signal) or killpg(0, signal) calls from reaching processes outside the sandbox that share the same process group. A malicious or compromised Flatpak app can use this to cause denial of service by terminating processes outside its sandbox, such as the desktop shell.

CVSS 3.1 · 5.7 Medium EPSS < 1% KEV · Not listed

Vendors

Flatpak Redhat

Products

Flatpak Enterprise Linux Rhel Els

CVE-2026-96281

Flatpak: flatpak: unprivileged active user can bypass anti-downgrade checks for system apps/runtimes

On a multi-user system, a user with an active local login session could downgrade a system-wide Flatpak app to an older version by removing the app's remote ref via the unprivileged system-helper RemoveLocalRef method, causing the anti-downgrade check to fail to find a reference date. A malicious local user could use this to expose other users of the same system to an app version with unfixed vulnerabilities.

CVSS 3.1 · 6.2 Medium EPSS < 1% KEV · Not listed

Vendors

Flatpak Redhat

Products

Flatpak Enterprise Linux Rhel Els

CVE-2026-96279

Flatpak: flatpak: path traversal issue in oci archive extraction via hardlinks

A malicious OCI registry can hardlink arbitrary host files into the extraction directory when a user installs or updates a Flatpak application from an OCI remote, allowing disclosure of arbitrary host file contents. For system-wide installs running as root, this includes sensitive files such as /etc/shadow.

CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed

Vendors

Flatpak Redhat

Products

Flatpak Enterprise Linux Rhel Els

CVE-2026-96276

Flatpak: flatpak: arbitrary write in host context via flatpak build-init

If a malicious SDK container declares an extension point with a crafted `directory` path, and a developer runs `flatpak build-init --writable-sdk --sdk-extension` with that SDK, attacker-chosen files could be written outside the working directory, since the target path is resolved via a function that allows `..` traversal.

CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed

Vendors

Flatpak Redhat

Products

Flatpak Enterprise Linux Rhel Els

CVE-2026-39977

flatpak-builder has a path traversal leading to arbitrary file read on host when installing licence files

flatpak-builder is a tool to build flatpaks from source. From 1.4.5 to before 1.4.8, the license-files manifest key takes an array of paths to user defined licence files relative to the source directory of the module. The paths from that array are resolved using g_file_resolve_relative_path() and validated to stay inside the source directory using two checks - g_file_get_relative_path() which does not resolve symlinks and g_file_query_file_type() with G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS which only applies to the final path component. The copy operation runs on host. This can be exploited by using a crafted manifest and/or source to read arbitrary files from the host and capture them into the build output. This vulnerability is fixed in 1.4.8.

CVSS 4.0 · 7.1 High EPSS < 1% KEV · Not listed

Vendors

Flatpak

Products

Flatpak-builder

CVE-2026-92162

Flatpak vulnerable to path traversal via unvalidated "arch" parameter in DeployAppstream

Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. Prior to version 1.18.1, on systems where at least one OCI remote is configured (most common on Fedora systems), a malicious local user in an active local session could use a crafted architecture name to trick the `flatpak-system-helper` process into creating a root-owned directory tree with contents determined by the OCI remote, plus a root-owned `lock` file and `icons` directory, outside the intended root directory. If this vulnerability is combined with other vulnerabilities also fixed in 1.18.1, the combination can lead to local root privilege escalation. This particular vulnerability is not believed to be exploitable if there are no OCI remotes configured (common on non-Fedora systems). Version 1.18.1 patches the issue.

CVSS 4.0 · 7.2 High EPSS < 1% KEV · Not listed

Vendors

Flatpak

Products

Flatpak

CVE-2026-96807

flatpak: Flatpak: Low integrity or availability impact via symlink manipulation

In Flatpak before 1.18.1, a malicious sandboxed app can replace ~/.var/app/$appid/.ld.so with a symlink, causing regenerate_ld_cache to write files at an arbitrary location. The filenames and content are not attacker controlled, making this hard to exploit.

CVSS 3.1 · 4 Medium EPSS < 1% KEV · Not listed

Vendors

Flatpak

Products

Flatpak

CVE-2026-96808

flatpak: Flatpak: Local privilege escalation via symlink traversal in revokefs writer

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.

CVSS 3.1 · 7.4 High EPSS < 1% KEV · Not listed

Vendors

Flatpak

Products

Flatpak

CVE-2026-90616

flatpak: Flatpak: Arbitrary code execution via missing symlink protection

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 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.

CVSS 3.1 · 7.4 High EPSS < 1% KEV · Not listed

Vendors

Flatpak

Products

Flatpak

CVE-2026-34078

Flatpak has a complete sandbox escape leading to host file access and code execution in the host context

Flatpak is a Linux application sandboxing and distribution framework. Prior to 1.16.4, the Flatpak portal accepts paths in the sandbox-expose options which can be app-controlled symlinks pointing at arbitrary paths. Flatpak run mounts the resolved host path in the sandbox. This gives apps access to all host files and can be used as a primitive to gain code execution in the host context. This vulnerability is fixed in 1.16.4.

CVSS 4.0 · 9.3 Critical EPSS 1.7% KEV · Not listed

Vendors

Flatpak

Products

Flatpak