# CVE-2026-97026: flatpak: Flatpak creates temporary child repository directories under the user cache with world-writable permissions (0777)

CVE-2026-97026 is fixed in flatpak on 1 platform, first by DEBIAN-CVE-2026-97026, released September 29, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-97026
- Priority: Routine
- CVSS: 3.9 (low)
- EPSS: 0.0010
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 28, 2026

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | flatpak Debian 13.5 (trixie) | 1.16.6-1~deb13u3 | [DEBIAN-CVE-2026-97026](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97026.md) | Sep 29, 2026 |
| Linux | flatpak Debian 14 | 1.18.4-1 | [DEBIAN-CVE-2026-97026](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97026.md) | Sep 29, 2026 |

---

Data as of 2026-11-08T00:53:09Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.