---
id: "CVE-2026-57201"
kind: "vulnerability"
aliases: ["CVE-2026-57201"]
title: "Asterisk: H.323 trace logging overflow lets a remote packet crash the process"
severity: "high"
cvss: 7.5
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["asterisk", "h323", "package", "self-hosted", "telephony"]
not_affected_if: ["default-config", "no-chan-ooh323", "port-not-public"]
published_at: "2026-10-27T17:17:02+00:00"
first_seen_at: "2026-10-27T17:32:46+00:00"
updated_at: "2026-10-27T17:34:34+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-57201", "first_seen_at": "2026-10-27T17:32:46+00:00"}]
---

# Asterisk: H.323 trace logging overflow lets a remote packet crash the process

A stack buffer overflow in Asterisk's H.323 ooTrace() logging function, reached through the chan_ooh323 channel driver, can be triggered by a crafted packet. The result described in the sources is a crash of the Asterisk process, denial of service.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check whether the chan_ooh323 module is installed: `ls /usr/lib/asterisk/modules/ | grep ooh323` (path may vary by install)
- Check the running version: `asterisk -rx "core show version"`
- Check whether the H.323 port is reachable from outside the network (default port unknown from sources)

## Fix

- Upgrade Asterisk to `20.20.1`, `21.12.3`, `22.10.1` or `23.4.1`, or Certified Asterisk `20.7-cert11` or `22.8-cert3`
- If chan_ooh323 is not needed, remove or do not load the module
- Block public access to the H.323 port until patched

## Timeline

- 2026-10-27T17:32:46+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-57201

## From the sources

Asterisk is an open source private branch exchange and telephony toolkit. Prior to Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3, a stack buffer overflow in the H.323 `ooTrace()` trace-logging function can occur when unbounded `vsprintf` writes into a fixed `2048-byte buffer`. A remote attacker may send a carefully crafted packet that causes the Asterisk process to crash. The `chan_ooh323` addon channel driver must be explicitly compiled and installed, which is not the default, and its port must be publicly reachable. This issue is fixed in Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_