# CVE-2026-76925: flatpak: In Flatpak before 1.18.1, a malicious sandboxed app can obtain arbitrary read and write access to files on the host,...

CVE-2026-76925 is fixed in 11 products on 1 platform, first by ALAS2023-2026-3143, released September 28, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-76925
- Priority: High
- CVSS: n/a (important)
- EPSS: 0.0010
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 28, 2026

## Description

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 . 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | flatpak amzn 2023 | 1.18.1-1.amzn2023 | [ALAS2023-2026-3143](https://patchblox.com/security/data/fix/linux/alas2023-2026-3143.md) | Sep 28, 2026 |
| Linux | flatpak-debuginfo amzn 2023 | 1.18.1-1.amzn2023 | [ALAS2023-2026-3143](https://patchblox.com/security/data/fix/linux/alas2023-2026-3143.md) | Sep 28, 2026 |
| Linux | flatpak-debugsource amzn 2023 | 1.18.1-1.amzn2023 | [ALAS2023-2026-3143](https://patchblox.com/security/data/fix/linux/alas2023-2026-3143.md) | Sep 28, 2026 |
| Linux | flatpak-devel amzn 2023 | 1.18.1-1.amzn2023 | [ALAS2023-2026-3143](https://patchblox.com/security/data/fix/linux/alas2023-2026-3143.md) | Sep 28, 2026 |
| Linux | flatpak-libs amzn 2023 | 1.18.1-1.amzn2023 | [ALAS2023-2026-3143](https://patchblox.com/security/data/fix/linux/alas2023-2026-3143.md) | Sep 28, 2026 |
| Linux | flatpak-libs-debuginfo amzn 2023 | 1.18.1-1.amzn2023 | [ALAS2023-2026-3143](https://patchblox.com/security/data/fix/linux/alas2023-2026-3143.md) | Sep 28, 2026 |
| Linux | flatpak-selinux amzn 2023 | 1.18.1-1.amzn2023 | [ALAS2023-2026-3143](https://patchblox.com/security/data/fix/linux/alas2023-2026-3143.md) | Sep 28, 2026 |
| Linux | flatpak-session-helper amzn 2023 | 1.18.1-1.amzn2023 | [ALAS2023-2026-3143](https://patchblox.com/security/data/fix/linux/alas2023-2026-3143.md) | Sep 28, 2026 |
| Linux | flatpak-session-helper-debuginfo amzn 2023 | 1.18.1-1.amzn2023 | [ALAS2023-2026-3143](https://patchblox.com/security/data/fix/linux/alas2023-2026-3143.md) | Sep 28, 2026 |
| Linux | flatpak-tests amzn 2023 | 1.18.1-1.amzn2023 | [ALAS2023-2026-3143](https://patchblox.com/security/data/fix/linux/alas2023-2026-3143.md) | Sep 28, 2026 |
| Linux | flatpak-tests-debuginfo amzn 2023 | 1.18.1-1.amzn2023 | [ALAS2023-2026-3143](https://patchblox.com/security/data/fix/linux/alas2023-2026-3143.md) | Sep 28, 2026 |

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Data as of 2026-11-12T01:51:14Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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