# CVE-2023-26122: safe-eval vulnerable to Sandbox Bypass due to improper input sanitization

> Attackers can bypass the safe-eval sandbox via prototype pollution to achieve remote code execution in applications using this library.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Apr 2023
- **Updated:** 7 Feb 2025
- **Also known as:** GHSA-79xf-67r4-q2jj

## What is CVE-2023-26122?

CVE-2023-26122 is a high-severity code injection vulnerability in safe-eval, published on 11 Apr 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

All versions of the package safe-eval are vulnerable to Sandbox Bypass due to improper input sanitization. The vulnerability is derived from prototype pollution exploitation.
Exploiting this vulnerability might result in remote code execution ("RCE").

**Vulnerable functions:**

__defineGetter__, stack(), toLocaleString(), propertyIsEnumerable.call(),  valueOf().

Weakness: CWE-1321 (Improperly Controlled Modification of Object Prototype Attributes), CWE-265

## Which versions are affected by CVE-2023-26122?

2 open source packages ship an affected version, including safe-eval. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `safe-eval` | npm | All versions to 0.4.2 | None |
| `safe-eval` | npm | All versions to 0.4.2 | None |

Products: Safe-Eval Project Safe-Eval.

## How do I fix CVE-2023-26122?

No fix has been published for CVE-2023-26122 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-26122 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-26122 exists.

## Other vulnerabilities in safe-eval

- [CVE-2017-16088](https://insights.sbomify.com/CVE-2017-16088/): Sandbox Breakout in safe-eval (critical 10.0)
- [CVE-2020-7710](https://insights.sbomify.com/CVE-2020-7710/): Sandbox Escape (high 8.1)
- [CVE-2023-26121](https://insights.sbomify.com/CVE-2023-26121/): safe-eval vulnerable to Prototype Pollution via the safeEval function (high 7.5)
- [CVE-2022-25904](https://insights.sbomify.com/CVE-2022-25904/): Prototype Pollution (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-26122 and fix it if it is affected.

What it is: CVE-2023-26122 is a high-severity code injection vulnerability in safe-eval, published on 11 Apr 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-26122 exists.

Affected packages and fixed versions:
- safe-eval (npm): affected all versions up to 0.4.2; no fix listed
- safe-eval (npm): affected all versions up to 0.4.2; no fix listed

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-2023-26122/ (Markdown: https://insights.sbomify.com/CVE-2023-26122/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-26122
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-26122
- OSV: https://osv.dev/vulnerability/CVE-2023-26122

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-26122/
Summaries are generated and may contain mistakes; the official description above is the record.