# CVE-2026-96808: Path traversal in Flatpak

> A local attacker can exploit symlink traversal in Flatpak's revokefs writer to modify system repository files and escalate privileges to root.

- **Severity:** High 7.4 (`CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 23 Sep 2026
- **Updated:** 23 Sep 2026
- **Also known as:** CLSA-2026-1790844951, CLSA-2026-1791735799, DEBIAN-CVE-2026-96808, GHSA-qrwq-7qwx-q9rp, OESA-2026-4569, OESA-2026-4571, UBUNTU-CVE-2026-96808

## What is CVE-2026-96808?

CVE-2026-96808 is a high-severity path traversal vulnerability in Flatpak, published on 23 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

Weakness: CWE-61 (UNIX Symbolic Link (Symlink) Following)

## Which versions are affected by CVE-2026-96808?


## How do I fix CVE-2026-96808?

Upgrade to a fixed version.

## Is CVE-2026-96808 being exploited?

There is no known exploitation of CVE-2026-96808 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-96808 and fix it if it is affected.

What it is: CVE-2026-96808 is a high-severity path traversal vulnerability in Flatpak, published on 23 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-96808 in the wild and no public exploit code.

Affected product: Flatpak. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-96808/ (Markdown: https://insights.sbomify.com/CVE-2026-96808/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-96808
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-96808
- OSV: https://osv.dev/vulnerability/CVE-2026-96808

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-96808/
Summaries are generated and may contain mistakes; the official description above is the record.