Auth bypass in Freeswitch
CVE-2026-49843
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, mod_verto's JSON-RPC handler bound the connection to the client-supplied sessid on the first frame, before the authentication gate. Binding inserts the connection into the global session hash and, on a key collision, drops the prior occupant of that slot — sending it a verto.punt, detaching its calls, and closing its socket. An unauthenticated network attacker who knows a target session UUID could therefore evict the legitimate client. This issue has been patched in version 1.11.1.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.005 (40.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
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-9457-fxr9-x78m (Third Party Advisory)
Frequently asked questions
- What is CVE-2026-49843?
- CVE-2026-49843 is a medium-severity vulnerability in Freeswitch, classified under Improper Authentication. CVSS score: 5.3/10. Published 2026-06-09.
- How severe is CVE-2026-49843?
- Medium severity. CVSS v3 base score is 5.3 out of 10.