Vulnerability · Published Sep 23, 2026 · Assigned by GitHub_M

CVE-2026-61834scim-patch: Mutation of Inherited Built-in Method Objects

Medium 4.3

In plain English

A medium-severity prototype pollution in scim-patch from thomaspoignant. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.3Medium

Exploit odds (30 days)0.4%top 66.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

scim-patch is a library for applying SCIM patch operations. Prior to 0.9.2, navigate() reads inherited properties and assign() uses prototype-chain membership checks while resolving attacker-controlled SCIM PATCH paths. A path or one of the dotted value keys beginning with an inherited property such as toString can therefore traverse into a shared built-in function object and add attacker-controlled properties, causing process-global mutation that may affect application logic reading inherited-method properties. This issue is fixed in version 0.9.2.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	scim-patch	0.9.2	GHSA-2mhw-wcx5-v3xj

Affected products (as reported)

Vendor	Product	Versions
thomaspoignant	scim-patch	< 0.9.2

Weakness: CWE-915, CWE-1321 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

References

https://github.com/thomaspoignant/scim-patch/security/advisories/GHSA-2mhw-wcx5-v3xj x_refsource_CONFIRM
https://github.com/thomaspoignant/scim-patch/pull/1127 x_refsource_MISC
https://github.com/thomaspoignant/scim-patch/commit/c86474f7a9b16191d939f59ba94eca6c6e63044b x_refsource_MISC
https://github.com/thomaspoignant/scim-patch/releases/tag/v0.9.2 x_refsource_MISC