# GHSA-j4mr-9xw3-c9jx: Out-of-bounds Read in base64-url

> An out-of-bounds read vulnerability in the base64-url library allows attackers to disclose sensitive memory contents by passing numeric inputs.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 31 May 2019

## What is GHSA-j4mr-9xw3-c9jx?

GHSA-j4mr-9xw3-c9jx is a vulnerability in base64-url, published on 31 May 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Versions of `base64-url` before 2.0.0 are vulnerable to out-of-bounds read as it allocates uninitialized Buffers when number is passed in input.

## Recommendation

Update to version 2.0.0 or later.

## Which versions are affected by GHSA-j4mr-9xw3-c9jx?

2 open source packages ship an affected version, including base64-url.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `base64-url` | npm | All versions | 2.0.0 |
| `base64-url` | npm | All versions | 2.0.0 |

## How do I fix GHSA-j4mr-9xw3-c9jx?

Upgrade base64-url to 2.0.0 or later.

## Is GHSA-j4mr-9xw3-c9jx being exploited?

There is no known exploitation of GHSA-j4mr-9xw3-c9jx in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-j4mr-9xw3-c9jx and fix it if it is affected.

What it is: GHSA-j4mr-9xw3-c9jx is a vulnerability in base64-url, published on 31 May 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-j4mr-9xw3-c9jx in the wild and no public exploit code.

Affected packages and fixed versions:
- base64-url (npm): affected all versions; fixed in 2.0.0
- base64-url (npm): affected all versions; fixed in 2.0.0

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/GHSA-j4mr-9xw3-c9jx/ (Markdown: https://insights.sbomify.com/GHSA-j4mr-9xw3-c9jx/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-j4mr-9xw3-c9jx

---
From sbomify Insights: https://insights.sbomify.com/GHSA-j4mr-9xw3-c9jx/
Summaries are generated and may contain mistakes; the official description above is the record.