# CVE-2026-48170: scimPatch vulnerable to prototype pollution via unfiltered keys in patch

> Prototype pollution in scim-patch allows attackers to modify Object.prototype via crafted SCIM PATCH requests, potentially leading to code execution.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Aug 2026
- **Updated:** 10 Aug 2026
- **Also known as:** GHSA-9m6g-wc8r-q59c

## What is CVE-2026-48170?

CVE-2026-48170 is a critical code injection vulnerability in thomaspoignant scim-patch, published on 7 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

`scim-patch`, a library to perform SCIM patch, prior to version 0.9.1 performs prototype pollution when applying a SCIM PATCH operation whose `value` object contains a key like `"__proto__.someProp"`. After one such patch,
`Object.prototype.someProp` is set process-wide, affecting every plain object in the Node process. Any service that calls `scimPatch()` on attacker-controlled JSON (i.e. any SCIM endpoint accepting `PATCH` from an external IdP) is exploitable on a stock Node runtime. Version 0.9.1 contains a patch. A workaround is available. Calling `Object.freeze(Object.prototype)` (and the same on `Array.prototype`, `Function.prototype`) at process startup neutralizes this class of bug — assignment to a frozen prototype becomes a silent no-op in sloppy mode or a `TypeError` in strict mode. Node's `--frozen-intrinsics` flag does this for built-ins automatically.

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

## Which versions are affected by CVE-2026-48170?

2 open source packages ship an affected version, including scim-patch.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `scim-patch` | npm | All versions | 0.9.1 |
| `scim-patch` | npm | All versions | 0.9.1 |

## How do I fix CVE-2026-48170?

Upgrade scim-patch to 0.9.1 or later.

## Is CVE-2026-48170 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48170 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-48170 and fix it if it is affected.

What it is: CVE-2026-48170 is a critical code injection vulnerability in thomaspoignant scim-patch, published on 7 Aug 2026. 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-2026-48170 exists.

Affected packages and fixed versions:
- scim-patch (npm): affected all versions; fixed in 0.9.1
- scim-patch (npm): affected all versions; fixed in 0.9.1

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-2026-48170/ (Markdown: https://insights.sbomify.com/CVE-2026-48170/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-48170
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-48170
- OSV: https://osv.dev/vulnerability/CVE-2026-48170

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-48170/
Summaries are generated and may contain mistakes; the official description above is the record.