Buffer overflow in Freeswitch
CVE-2026-49841
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, the mod_verto HTTP request handler allocates a fixed 2 MiB buffer for a POST application/x-www-form-urlencoded body but accepts Content-Length up to just under 10 MiB. The body-read loop is bounded by Content-Length rather than the buffer size, producing an attacker-controlled heap overflow of up to ~8 MiB -- before the HTTP basic-auth check runs. This issue has been patched in version 1.11.1.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (46.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.8% 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: 0.006 · 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-wfrq-qvg2-f88f (Third Party Advisory)
Frequently asked questions
- What is CVE-2026-49841?
- CVE-2026-49841 is a critical-severity vulnerability in Freeswitch, classified under Heap-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-06-09.
- How severe is CVE-2026-49841?
- Critical severity. CVSS v3 base score is 9.8 out of 10.