CVE-2026-116574
FreeSWITCH: Off-by-one heap write in core XML serialization of four-byte UTF-8 sequences
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_xml_ampencode() reserved only ten bytes for the widest numeric character reference produced from a four-byte UTF-8 sequence, omitting space for the terminating NUL. When remote-supplied text was serialized at the exact buffer-growth boundary, the terminator wrote one byte beyond the heap allocation. Reachable surfaces include mod_xml_cdr, conference and formatted CDR XML, XML Event Socket output, and XML API output that serializes caller-controlled values. The fixed zero-byte write can abort the process or truncate an adjacent object, while remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
5.9
FreeSWITCH: Off-by-one heap write in core XML serialization of four-byte UTF-8 sequences
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_xml_ampencode() reserved only ten bytes for the widest numeric character reference produced from a four-byte UTF-8 sequence, omitting space for the terminating NUL. When remote-supplied text was serialized at the exact buffer-growth boundary, the terminator wrote one byte beyond the heap allocation. Reachable surfaces include mod_xml_cdr, conference and formatted CDR XML, XML Event Socket output, and XML API output that serializes caller-controlled values. The fixed zero-byte write can abort the process or truncate an adjacent object, while remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.
- Record
CVE-2026-116574- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-193, CWE-787
- Updated
- 2026-11-05
EUVDEUVD-2026-117731
5.9
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_xml_ampencode() reserved only ten bytes for the widest numeric character reference produced from a four-byte UTF-8 sequence, omitting space for the terminating NUL. When remote-supplied text was serialized at the exact buffer-growth boundary, the terminator wrote one byte beyond the heap allocation. Reachable surfaces include mod_xml_cdr, conference and formatted CDR XML, XML Event Socket output, and XML API output that serializes caller-controlled values. The fixed zero-byte write can abort the process or truncate an adjacent object, while remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.
- Record
EUVD-2026-117731- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H - Updated
- 2026-11-05
NVD
5.9
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_xml_ampencode() reserved only ten bytes for the widest numeric character reference produced from a four-byte UTF-8 sequence, omitting space for the terminating NUL. When remote-supplied text was serialized at the exact buffer-growth boundary, the terminator wrote one byte beyond the heap allocation. Reachable surfaces include mod_xml_cdr, conference and formatted CDR XML, XML Event Socket output, and XML API output that serializes caller-controlled values. The fixed zero-byte write can abort the process or truncate an adjacent object, while remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.
- Record
CVE-2026-116574- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-193, CWE-787
- Updated
- 2026-11-05
OSV
5.9
FreeSWITCH: Off-by-one heap write in core XML serialization of four-byte UTF-8 sequences
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_xml_ampencode() reserved only ten bytes for the widest numeric character reference produced from a four-byte UTF-8 sequence, omitting space for the terminating NUL. When remote-supplied text was serialized at the exact buffer-growth boundary, the terminator wrote one byte beyond the heap allocation. Reachable surfaces include mod_xml_cdr, conference and formatted CDR XML, XML Event Socket output, and XML API output that serializes caller-controlled values. The fixed zero-byte write can abort the process or truncate an adjacent object, while remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.
- Record
CVE-2026-116574- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-193, CWE-787
- Updated
- 2026-11-07
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, references | NVD, OSV | |
| first indexed | CVE List, EUVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-116574 is a medium vulnerability (CVSS 5.9) in Signalwire Freeswitch, published November 5, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.38%, the 32nd percentile. No source names a fixed version.
References
github.com/signalwire/freeswitch/security/advisories/GHSA-r6vh-qmwm-h3cc
github.com/signalwire/freeswitch/commit/28fcfd26246c112fa4b9e698433d09e4836ca1b5
github.com/signalwire/freeswitch/releases/tag/v1.11.2
github.com/CVEProject/cvelistV5/tree/main/cves/2026/116xxx/CVE-2026-116574.json
nvd.nist.gov/vuln/detail/CVE-2026-116574