Padloc: Prototype pollution via SCIM PATCH paths
Summary
Padloc versions 4.0.0 before 4.3.1 contain a prototype pollution vulnerability (CWE-1321) in the SCIM provisioning interface. An attacker who holds a SCIM token can send crafted PATCH paths such as __proto__ or constructor.prototype, which modify Object.prototype in the shared server process. This can disrupt requests for all organizations served by the same Padloc instance.
Affected
- Padloc 4.0.0 to before 4.3.1
Fixed in
- Padloc 4.3.1 (listed as unaffected by the CNA VulnCheck)
Workaround
- No vendor workaround documented. Upgrade to 4.3.1 or later.
- Interim measure (recommendation, not from the vendor): restrict SCIM access to the identity provider's address range, rotate SCIM tokens and review who holds them.
Exploitation
- No evidence of active exploitation found, but not confirmed.
- Public proof-of-concept code: no evidence found.
- CISA KEV status: not checked.
Our recommendation
- Identify all Padloc instances and their versions and check whether SCIM provisioning is enabled.
- If SCIM is enabled, upgrade to 4.3.1 or later, prioritising instances reachable from the internet.
- Restrict SCIM access to the identity provider, rotate SCIM tokens and review logs for unexpected PATCH requests.
- Monitor the GitHub advisory GHSA-crhv-mjrg-8vwm for updates.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- CVE Record CVE-2026-126570 www.cve.org
- GitHub Security Advisory GHSA-crhv-mjrg-8vwm github.com
- Fix commit 7dd3d230 github.com
- VulnCheck advisory www.vulncheck.com
- Vulnerable code: server scim.ts (v4.3.0) github.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 07:26.
Original description (NVD)
Padloc 4.0.0 before 4.3.1 contains a prototype pollution vulnerability that allows SCIM token holders to modify Object.prototype by sending crafted SCIM PATCH paths to ScimServer._handleScimUsersPatch(). Attackers can supply paths like __proto__.x or constructor.prototype.x passed to setPath() to pollute the shared server process, disrupting requests for all other organizations.
NVD references (5)
- https://github.com/padloc/padloc/blob/v4.3.0/packages/core/src/util.ts#L239-L251
- https://github.com/padloc/padloc/blob/v4.3.0/packages/server/src/scim.ts#L421-L428
- https://github.com/padloc/padloc/commit/7dd3d230ef299c71ac215c802600b5f2358f7ba3
- https://github.com/padloc/padloc/security/advisories/GHSA-crhv-mjrg-8vwm
- https://www.vulncheck.com/advisories/padloc-4.0.0-before-4.3.1-prototype-pollution-via-scim-patch-setpath
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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