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.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
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
Which versions are affected by CVE-2026-48170?
2 open source packages ship an affected version, including scim-patch.
| Package | 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.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-48170 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48170 exists.
Sources
Also known as GHSA-9m6g-wc8r-q59c.