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.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| freeswitch signalwire |
< 1.11.2 (affected) | CNA: GitHub_M |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 5.9 medium |
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H | CNA: GitHub_M |
| 3.1 / 5.9 medium |
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H | NVD: [email protected] |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/signalwire/freeswitch/security/advisories/GHSA-r6vh-qmwm-h3ccCNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/signalwire/freeswitch/commit/28fcfd26246c112fa4b9e698433d09e4836ca1b5CNA: GitHub_M · x_refsource_MISC
- https://github.com/signalwire/freeswitch/releases/tag/v1.11.2CNA: GitHub_M · x_refsource_MISC
- https://github.com/signalwire/freeswitch/commit/28fcfd26246c112fa4b9e698433d09e4836ca1b5[email protected]
- https://github.com/signalwire/freeswitch/releases/tag/v1.11.2[email protected]
- https://github.com/signalwire/freeswitch/security/advisories/GHSA-r6vh-qmwm-h3cc[email protected]
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