CVSS 3.1
9.1 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:HCVE-2026-49840
Critical (9.1) in freeswitch freeswitch. EPSS 0.3% chance of exploitation in the next 30 days.
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, esl_recv_event() parses Content-Length with atol() and passes the result straight to malloc(len + 1) with no sign or magnitude check. A malicious or man-in-the-middle ESL peer can send a frame with a negative Content-Length to corrupt the heap of, or crash, any process linked against libesl, before the client has authenticated to that peer. This issue has been patched in version 1.11.1.
Severity
- EPSS
- 0.3% chance of exploitation in the next 30 days; higher than 23% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-20, CWE-122, CWE-195, CWE-787
- Published
- Modified
- Record from
- the NVD, synced
Affected
- freeswitch:freeswitch