# CVE-2026-96276: flatpak: If a malicious SDK container declares an extension point with a crafted `directory` path, and a developer runs `flatp...

CVE-2026-96276 is fixed in flatpak on 1 platform, first by DEBIAN-CVE-2026-96276, released September 23, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-96276
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0044
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 23, 2026

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | flatpak Debian 13.5 (trixie) | 1.16.6-1~deb13u2 | [DEBIAN-CVE-2026-96276](https://patchblox.com/security/data/fix/linux/debian-cve-2026-96276.md) | Sep 23, 2026 |
| Linux | flatpak Debian 14 | 1.18.1-1 | [DEBIAN-CVE-2026-96276](https://patchblox.com/security/data/fix/linux/debian-cve-2026-96276.md) | Sep 23, 2026 |
| Linux | flatpak sles 15.6 | 1.16.6-150600.3.12.1 | [SUSE-SU-2026:4944-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4944-1.md) | Nov 7, 2026 |
| Linux | flatpak sles 15.7 | 1.16.6-150600.3.12.1 | [SUSE-SU-2026:4944-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4944-1.md) | Nov 7, 2026 |

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Data as of 2026-11-08T13:06:02Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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