Vulnerability in Freeswitch
CVE-2026-49847
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 version 1.11.1, a single unauthenticated WebSocket frame containing a deeply nested JSON document crashes the FreeSWITCH process via stack overflow, terminating all calls and sessions on the host. The recursion drives the worker thread's stack pointer into the stack guard page, raising SIGSEGV from the kernel before any usable write primitive develops. This issue has been patched in version 1.11.1.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (42.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 42.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001
Affected products
- Freeswitch
- Signalwire Freeswitch — versions < 1.11.1
Weakness classification (CWE)
References
- github.com/signalwire/freeswitch/releases/tag/v1.11.1 (Release Notes)
- github.com/signalwire/freeswitch/security/advisories/GHSA-2v74-pcgh-75wg (Third Party Advisory)
Frequently asked questions
- What is CVE-2026-49847?
- CVE-2026-49847 is a high-severity vulnerability in Freeswitch, classified under Uncontrolled Recursion. CVSS score: 7.5/10. Published 2026-06-09.
- How severe is CVE-2026-49847?
- High severity. CVSS v3 base score is 7.5 out of 10.