# CVE-2026-76925: flatpak-tests: Package updates are available for Amazon Linux 2023 that fix the following vulnerabilities: CVE-2026-96808: In Flatp... 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 Package updates are available for Amazon Linux 2023 that fix the following vulnerabilities: CVE-2026-96808: 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. CVE-2026-96275: 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. CVE-2026-90616: 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. CVE-2026-76925: A flaw was found in Flatpak. A Time-of-check to time-of-use (TOCTOU) race condition exists in the `org.freedesktop.Flatpak.SystemHelper` component. This vulnerability occurs because a privileged `chmod` operation executes before the OSTree repository validation within the `Deploy()` function. An attacker can exploit this timing window to redirect symlinks to arbitrary files, potentially leading to unauthorized file manipulation or information disclosure. ## 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 | --- Data as of 2026-11-10T13:56:55Z UTC. 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