CVE-2026-116781
FreeSWITCH: Pre-authentication out-of-bounds writes in mod_xml_rpc WebSocket frame parsing
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, ws_read_frame() unmasked a WebSocket payload by iterating wsh->datalen, which included frame headers, while indexing from the payload pointer. A masked frame filling the 64 KiB receive buffer could therefore XOR up to 14 bytes beyond the buffer, and the exact-capacity case also wrote a terminating NUL one byte out of bounds. The flaw is reachable before authentication when mod_xml_rpc and its opt-in WebSocket endpoint are enabled, while both features are disabled in the stock configuration. The writes remain within the same connection handle's adjacent outbound buffer, so neither a process crash nor cross-session disclosure has been demonstrated. This issue is fixed in version 1.11.2.
INFO
Published Date :
Nov. 5, 2026, 8:17 p.m.
Last Modified :
Nov. 5, 2026, 10:38 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update FreeSWITCH to version 1.11.2.
- Enable WebSocket endpoint only if required.
- Ensure mod_xml_rpc is disabled if unused.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-116781.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-116781 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-116781
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-116781 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-116781 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Nov. 05, 2026
Action Type Old Value New Value 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, ws_read_frame() unmasked a WebSocket payload by iterating wsh->datalen, which included frame headers, while indexing from the payload pointer. A masked frame filling the 64 KiB receive buffer could therefore XOR up to 14 bytes beyond the buffer, and the exact-capacity case also wrote a terminating NUL one byte out of bounds. The flaw is reachable before authentication when mod_xml_rpc and its opt-in WebSocket endpoint are enabled, while both features are disabled in the stock configuration. The writes remain within the same connection handle's adjacent outbound buffer, so neither a process crash nor cross-session disclosure has been demonstrated. This issue is fixed in version 1.11.2. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Added CWE CWE-787 Added CWE CWE-193 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/116xxx/CVE-2026-116781.json">CVE-2026-116781</a> Added Reference https://github.com/signalwire/freeswitch/commit/fb9f37b9c7869630ee52a3ae87399fbbf99ad74d Added Reference https://github.com/signalwire/freeswitch/releases/tag/v1.11.2 Added Reference https://github.com/signalwire/freeswitch/security/advisories/GHSA-4cg6-rvh2-cw74