CVE-2026-116780

FreeSWITCH: Heap out-of-bounds read in FreeSWITCH core variable expansion via `${variable:offset}` slicing

Published Nov 5, 2026 CVSS 3.1 · 2.7 Low EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Freeswitch
Freeswitch freeswitch
CPEs cpe:2.3:a:freeswitch:freeswitch:*:*:*:*:*:*:*:*
Vendors & Products Freeswitch
Freeswitch freeswitch
Type Values Removed Values Added
First Time appeared Signalwire
Signalwire freeswitch
Vendors & Products Signalwire
Signalwire freeswitch
Type Values Removed Values Added
Description 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 ${variable:offset} exceeded the variable value's length. The following length calculation and copy appended adjacent heap memory to the expansion result, potentially exposing channel variables, credentials, allocator data, and pointer bytes. The flaw is reachable through configuration templates that slice remote input and through authenticated Event Socket eval or Event Socket expand commands; the separate channel-variable expander used by ordinary dialplan slicing is unaffected. The requester cannot choose adjacent memory and disclosure stops at a zero byte, but repeated expansion can influence the layout. This issue is fixed in version 1.11.2.
Title FreeSWITCH: Heap out-of-bounds read in FreeSWITCH core variable expansion via `${variable:offset}` slicing
Weaknesses CWE-125
CWE-200
References
Metrics cvssV3_1

{'score': 2.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 9, 2026, 6:07 PM
Reserved
Oct 26, 2026, 9:53 PM
Status
Analyzed
Published
Nov 5, 2026, 8:17 PM
Modified
Nov 10, 2026, 6:57 PM