# CVE-2026-116788: FreeSWITCH integer underflow in XML decode

Source: https://junglewise.ai/threats/cve-2026-116788-freeswitch-is-an-open-source-software-telecommunications  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-05. Updated: 2026-11-05  
License: CC BY 4.0 with a link back

CVE-2026-116788 · Severity: high · CVSS 8.2 · Published 2026-11-05

FreeSWITCH is an open-source telecommunications platform that handles VoIP calls and media. An integer underflow in XML parsing can cause a crash that terminates the process and interrupts all active calls when processing specially crafted SIP requests with XML entities. An attacker without authentication can trigger this by sending a malicious SIP PUBLISH message to a presence-enabled profile.

Technologies: [SignalWire FreeSWITCH](https://junglewise.ai/threats/technologies/freeswitch). Vendors: [SignalWire](https://junglewise.ai/threats/vendors/signalwire).

## Quick answers

**Is CVE-2026-116788 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-116788 being exploited in the wild.

**How severe is CVE-2026-116788?** High severity, with a CVSS score of 8.2, published 5 November 2026.

**Which products and versions are affected?** SignalWire FreeSWITCH before 1.11.2.

**Is there a fix for CVE-2026-116788?** Yes: fixed in 1.11.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-116788 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-116788?** Check whether you run SignalWire FreeSWITCH at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 1.11.2

## Technical details

An integer underflow in the switch_xml_decode() function occurs when an XML entity is declared with an empty replacement value, leading to undersized heap allocation. When subsequent data is copied into this buffer, a heap overflow results. The vulnerability requires network reachability to a SIP profile with presence management enabled and DTD processing permitted; exploitation corrupts heap memory and crashes the process.

## Affected products

- SignalWire FreeSWITCH before 1.11.2

## Timeline

- 2026-11-05: disclosed

## References

- [https://github.com/signalwire/freeswitch/commit/587474a1584488f0c04201e6e61efe76aa5bda01](https://github.com/signalwire/freeswitch/commit/587474a1584488f0c04201e6e61efe76aa5bda01)
- [https://github.com/signalwire/freeswitch/releases/tag/v1.11.2](https://github.com/signalwire/freeswitch/releases/tag/v1.11.2)

## Related threats

- [FreeSWITCH ICE integrity validation bypass](https://junglewise.ai/threats/cve-2026-116790-freeswitch-is-a-software-defined-telecom-stack-enabling-the)
- [FreeSWITCH DTLS fingerprint validation bypass in server role](https://junglewise.ai/threats/cve-2026-116789-freeswitch-is-a-software-defined-telecom-stack-enabling-the)
- [FreeSWITCH mod_event_socket denial of service via Content-Length](https://junglewise.ai/threats/cve-2026-116787-freeswitch-is-a-software-defined-telecom-stack-enabling-the)
- [FreeSWITCH command injection via SIP REFER URI parameters](https://junglewise.ai/threats/cve-2026-116786-freeswitch-is-a-software-defined-telecom-stack-enabling-the)
- [FreeSWITCH WebSocket frame length heap overflow](https://junglewise.ai/threats/cve-2026-116785-freeswitch-is-a-software-defined-telecom-stack-enabling-the)