CVE-2026-49848 FreeSWITCH: Pre-authentication `userVariables` injection in `mod_verto`
Attackers can inject user variables during failed authentication attempts that persist into subsequent successful logins, potentially escalating privileges or bypassing security controls.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-49848?
CVE-2026-49848 is a medium-severity authentication bypass vulnerability in signalwire freeswitch, published on 9 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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 check_auth userauth branch wrote request-supplied userVariables into the connection state before comparing the supplied password. The writes are append-only and the connection is not closed on a failed compare, so values declared on bad-password attempts persisted on the same WebSocket and carried into a subsequent successful login on that connection. This issue has been patched in version 1.11.1.
Weakness: CWE-287
Which versions are affected by CVE-2026-49848?
It affects 1 product.
Products include Freeswitch Freeswitch.
How do I fix CVE-2026-49848?
No fix has been published for CVE-2026-49848 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-49848 being exploited?
There is no known exploitation of CVE-2026-49848 in the wild and no public exploit code.
Other vulnerabilities in signalwire freeswitch
- CVE-2026-49841 FreeSWITCH: Pre-authentication heap buffer overflow in `mod_verto` HTTP POST body read
- CVE-2019-19492 Hardcoded credentials in n/a
- CVE-2026-49840 FreeSWITCH: Pre-authentication heap buffer overflow in libesl `Content-Length` parsing
- CVE-2021-41145 FreeSWITCH susceptible to Denial of Service via SIP flooding
- CVE-2026-45771 Freeswitch Denial-of-Service in SIP PUBLISH Requests via XML Entity Expansion
Sources
Also known as GHSA-j38x-xm7f-9p2f.