CVE-2025-27591 Below has Incorrect Permission Assignment for Critical Resource
Local unprivileged users can escalate to root privileges via symlink attacks on a world-writable log directory in the Below service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-27591?
CVE-2025-27591 is a medium-severity vulnerability in Meta Platforms, Inc below, published on 11 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A privilege escalation vulnerability existed in the Below service prior to v0.9.0 due to the creation of a world-writable directory at /var/log/below. This could have allowed local unprivileged users to escalate to root privileges through symlink attacks that manipulate files such as /etc/shadow.
Weakness: CWE-732
Which versions are affected by CVE-2025-27591?
3 open source packages ship an affected version, including below. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
below crates.io | All versions | 0.9.0 |
below crates.io | All versions | 0.9.0 |
below crates.io | From 0.0.0-0 | 0.9.0 |
Linux distribution packages (1)
cargo-audit-advisory-db openSUSE:Tumbleweed | All versions | 20260213-1.1 |
Products include Facebook Below.
How do I fix CVE-2025-27591?
Upgrade below to 0.9.0 or later.
Is CVE-2025-27591 being exploited?
There is no known exploitation of CVE-2025-27591 in the wild and no public exploit code.
Public exploit code: 19 proofs of concept on GitHub.
Sources
Also known as GHSA-9mc5-7qhg-fp3w, RUSTSEC-2025-0149, openSUSE-SU-2026:10194-1.