# CVE-2026-125358: Universal-modder before e88f687 Cross-Site WebSocket Command Execution via HostLink

Status: published. Published: 2026-11-09. Updated: 2026-11-09.

Universal-modder before commit e88f6876745427321eb755ebc98276063a962d8a contains a missing WebSocket Origin validation vulnerability in the HostLink class of its passthrough example mods that allows remote attackers to execute Minecraft commands. Any web page open in the player's browser can connect cross-site to the unauthenticated loopback WebSocket and send cmd messages that WorldBridge.command() runs with operator authority.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/rehan-remade/universal-modder/commit/e88f6876745427321eb755ebc98276063a962d8a

## Affected products and versions

- rehan-remade / universal-modder: ≥ 0; < e88f6876745427321eb755ebc98276063a962d8a (affected, git). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 7.2 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 8.1 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-1385

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/rehan-remade/universal-modder/security/advisories/GHSA-wjf6-3h6v-4gq9 (CNA: VulnCheck; vendor-advisory)

- https://github.com/rehan-remade/universal-modder/commit/e88f6876745427321eb755ebc98276063a962d8a (CNA: VulnCheck; patch)

- https://github.com/rehan-remade/universal-modder/blob/edf45f6a26cb047886d9d7bcba392c328fc3d317/examples/minecraft-gta5-passthrough/mc/src/client/java/dev/rehan/passthrough/client/HostLink.java#L54-L72 (CNA: VulnCheck; technical-description)

- https://www.vulncheck.com/advisories/universal-modder-before-e88f687-cross-site-websocket-command-execution-via-hostlink (CNA: VulnCheck; third-party-advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-125358; retrieved 2026-11-10; source updated 2026-11-09

Revision: ba33f9d61d27b016b8e8824a9b9938cd98a4661a10857a1c1bedfb285251e927

Canonical: https://y2.dev/cve/CVE-2026-125358

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