---
id: CVE-2026-116780
title: >-
  FreeSWITCH: Heap out-of-bounds read in FreeSWITCH core variable expansion via
  `${variable:offset}` slicing
summary: >-
  FreeSWITCH is a Software Defined Telecom Stack enabling the digital
  transformation from proprietary telecom switches to a software implementation
  that runs on any commodity hardware. Prior to 1.11.2,
  switch_event_expand_headers_check() a…
severity: low
cvss: 2.7
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N'
cvssSource: cna
cwe:
  - CWE-125
  - CWE-200
vendor: signalwire
product: freeswitch
affected:
  - freeswitch < 1.11.2
published: '2026-11-05'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T19:34:21.327Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-116780'
references:
  - url: >-
      https://github.com/signalwire/freeswitch/security/advisories/GHSA-2p6g-9c8q-232p
    label: >-
      https://github.com/signalwire/freeswitch/security/advisories/GHSA-2p6g-9c8q-232p
  - url: >-
      https://github.com/signalwire/freeswitch/commit/30cdb387ae0fac0cbbeb6ac05416aaffb9252258
    label: >-
      https://github.com/signalwire/freeswitch/commit/30cdb387ae0fac0cbbeb6ac05416aaffb9252258
  - url: 'https://github.com/signalwire/freeswitch/releases/tag/v1.11.2'
    label: 'https://github.com/signalwire/freeswitch/releases/tag/v1.11.2'
tags:
  - cve.org
ingestedAt: '2026-11-05T22:38:31.554Z'
---

## Overview

FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. Prior to 1.11.2, switch_event_expand_headers_check() advanced beyond its heap copy when a positive offset in ${variable:offset} exceeded the variable value's length. The following length calculation and copy appended adjacent heap memory to the expansion result, potentially exposing channel variables, credentials, allocator data, and pointer bytes. The flaw is reachable through configuration templates that slice remote input and through authenticated Event Socket eval or Event Socket expand commands; the separate channel-variable expander used by ordinary dialplan slicing is unaffected. The requester cannot choose adjacent memory and disclosure stops at a zero byte, but repeated expansion can influence the layout. This issue is fixed in version 1.11.2.

## Affected

- `freeswitch < 1.11.2`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.