CVE-2026-27606 Rollup 4 has Arbitrary File Write via Path Traversal
Attackers can overwrite arbitrary files via path traversal in Rollup, potentially leading to persistent remote code execution on the host system.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-27606?
CVE-2026-27606 is a high-severity path traversal vulnerability in rollup, published on 25 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Rollup is a module bundler for JavaScript. Versions prior to 2.80.0, 3.30.0, and 4.59.0 of the Rollup module bundler (specifically v4.x and present in current source) is vulnerable to an Arbitrary File Write via Path Traversal. Insecure file name sanitization in the core engine allows an attacker to control output filenames (e.g., via CLI named inputs, manual chunk aliases, or malicious plugins) and use traversal sequences (`../`) to overwrite files anywhere on the host filesystem that the build process has permissions for. This can lead to persistent Remote Code Execution (RCE) by overwriting critical system or user configuration files. Versions 2.80.0, 3.30.0, and 4.59.0 contain a patch for the issue.
Weakness: CWE-22
Which versions are affected by CVE-2026-27606?
6 open source packages ship an affected version, including rollup. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
rollup npm | All versions | 2.80.0 |
rollup npm | All versions | 2.80.0 |
rollup npm | From 3.0.0 | 3.30.0 |
rollup npm | From 3.0.0 | 3.30.0 |
rollup npm | From 4.0.0 | 4.59.0 |
rollup npm | From 4.0.0 | 4.59.0 |
Linux distribution packages (1)
heroic-games-launcher openSUSE:Tumbleweed | All versions | 2.20.0-2.1 |
Products include Rollupjs Rollup.
How do I fix CVE-2026-27606?
Upgrade rollup to a fixed version for your release line: 2.80.0, 3.30.0 or 4.59.0.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-27606 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-27606 exists.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in rollup
Sources
Also known as CLSA-2026-1775176078, CLSA-2026-1775521840, CLSA-2026-1775521842, CLSA-2026-1784596332, CLSA-2026-1792160912, CLSA-2026-1792161062 and 23 more.