CVE-2026-116785: freeswitch Heap Overflow — Fix

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() decoded a WebSocket frame's 64-bit extended payload length with a 32-bit byte swap and narrowed the result into a signed length. A value whose surviving low word became negative bypassed the signed size check and was reinterpreted as an enormous unsigned count, causing client bytes to overwrite memory beyond the 64 KiB receive buffer. Any client completing a /socket WebSocket upgrade on an enabled mod_xml_rpc endpoint reached the parser before HTTP authentication; both the module and WebSocket endpoint are disabled by default. The heap overwrite can corrupt connection pointers and crash FreeSWITCH, ending every concurrent session, although remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.

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CVSS v3.1 Score

9.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

EPSS — Exploit Prediction

0.0109

Probability of exploitation

0.66%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-122 CWE-122

CWE-681 CWE-681

CWE-787 Out-of-bounds Write

Affected Products

Vendor	Product	Versions
freeswitch	freeswitch	< 1.11.2

References

Advisories & Patches

https://github.com/signalwire/freeswitch/commit/d557ca6d29e6da4f10824dc158100906a592b91a https://github.com/signalwire/freeswitch/security/advisories/GHSA-jj89-q47c-gh94

Other References

https://github.com/signalwire/freeswitch/releases/tag/v1.11.2

Frequently Asked Questions

What is CVE-2026-116785? +

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() decoded a WebSocket frame's 64-bit extended payload length with a 32-bit byte swap and narrowed the result into a signed length. A value whose surviving low word became negative bypassed the signed size check and was reinterpreted as an enormous unsigned count, causing client bytes to overwrite memory beyond the 64 KiB receive buffer. Any client completing a /socket WebSocket upgrade on an enabled mod_xml_rpc endpoint reached the parser before HTTP authentication; both the module and WebSocket endpoint are disabled by default. The heap overwrite can corrupt connection pointers and crash FreeSWITCH, ending every concurrent session, although remote code execution has not been demonstrated. This issue is fixed in version 1.11.2. It has a CVSS v3.1 base score of 9.1 (CRITICAL).

How severe is CVE-2026-116785? +

CVE-2026-116785 has a CVSS v3.1 score of 9.1 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0109, placing it in the 1th percentile for exploitation probability.

What products are affected by CVE-2026-116785? +

CVE-2026-116785 affects products from freeswitch, specifically: freeswitch. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-116785? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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