# CVE-2017-16119: Regular Expression Denial of Service in fresh

> Attackers can cause a denial of service in applications using the Fresh module by sending specially crafted input that blocks the event loop.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Jun 2018
- **Updated:** 8 Oct 2026
- **Also known as:** AZL-44892, CLSA-2026-1771805410, CLSA-2026-1773706628, CLSA-2026-1784596355, CLSA-2026-1784769497, CLSA-2026-1789159763, DEBIAN-CVE-2017-16119, GHSA-9qj9-36jm-prpv, ROOT-APP-NPM-CVE-2017-16119, UBUNTU-CVE-2017-16119

## What is CVE-2017-16119?

CVE-2017-16119 is a high-severity denial of service vulnerability in HackerOne fresh node module, published on 7 Jun 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Fresh is a module used by the Express.js framework for HTTP response freshness testing. It is vulnerable to a regular expression denial of service when it is passed specially crafted input to parse. This causes the event loop to be blocked causing a denial of service condition.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2017-16119?

2 open source packages ship an affected version, including fresh. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `fresh` | npm | All versions | 0.5.2 |
| `fresh` | npm | All versions | 0.5.2 |

Products: Fresh Project Fresh.

## How do I fix CVE-2017-16119?

Upgrade fresh to 0.5.2 or later.

## Is CVE-2017-16119 being exploited?

There is no known exploitation of CVE-2017-16119 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-16119 and fix it if it is affected.

What it is: CVE-2017-16119 is a high-severity denial of service vulnerability in HackerOne fresh node module, published on 7 Jun 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2017-16119 in the wild and no public exploit code.

Affected packages and fixed versions:
- fresh (npm): affected all versions; fixed in 0.5.2
- fresh (npm): affected all versions; fixed in 0.5.2

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-2017-16119/ (Markdown: https://insights.sbomify.com/CVE-2017-16119/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-16119
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-16119
- OSV: https://osv.dev/vulnerability/CVE-2017-16119

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-16119/
Summaries are generated and may contain mistakes; the official description above is the record.