VulnSocial

CVE-2026-49840Patch(freeswitch / freeswitch)

LOWCVSS 9.1 · CRITICAL

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch freeswitch freeswitch systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD 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, 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.

freeswitch CVEsBack to dashboard
0.5/ 10 priority

Sources & remediation

Vendor / third-party advisories
Other references
Weakness type (CWE)
CWE-20CWE-122CWE-195CWE-787

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • freeswitch

Threat summary

  • Patch or workaround signal is available
  • 1 mentions across 1 observed day

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 1 signal
  • 1 total mentions across 1 day

Affected systems

Vendors
freeswitch
Products
freeswitch

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-06-16: 1Patch / Workaround · 2026-06-16: 1Technical Details · 2026-06-16: 106-16
Signal classification1 categories
Patch
1100.0%
Referenced assets1 URL
By indicator
Full discourse1 post
  • Daily CyberSecurity@the_yellow_fall
    Patch

    Two pre-auth FreeSWITCH heap buffer overflow bugs (CVE-2026-49841, CVE-2026-49840) hit mod_verto and libesl. Update to v1.11.1 to stay safe. #FreeSWITCH #CVE202649841 #CVE202649840 #HeapOverflow #InfoSec https://securityonline.info/freeswitch-heap-buffer-overflow-cve-2026-49841 https://t.co/V1xpbXh4I8

    Post summary

    Two pre‑authentication heap buffer overflow vulnerabilities (CVE‑2026‑49840 & CVE‑2026‑49841) were disclosed for FreeSWITCH; users are advised to upgrade to v1.11.1.

    01032247
    12.8K followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
Appfreeswitchfreeswitch---

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