CVE-2026-49840

Improper input validation in Freeswitch

CVSS score

9.1

EPSS probability

%0.5

Risk score

0.0

Published

4 mo ago

Overview Public Exploits (0)Newsroom Vulnerability Timeline

Patch status has not yet been verified

Resmî kaynaklarda yeterli kanıt bulunamadı. Bu sonuç “yama yok” anlamına gelmez.

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Vulnerability description

DayBreach CVE AI Research

CVE-2026-49840 has vendor, distribution, patch and security-source records on file. We can compare them and prepare an explanation linked to the evidence.

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.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-49840 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

ID	VENDOR	PRODUCT	ACTION
1	freeswitch	freeswitch	View

Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCORE	VERSION	SEVERITY	VECTOR	SOURCE
9.1	CVSS V31	CRITICAL	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H	NVD

Patch and Remediation Guide

Solution & Remediation Advisory

Patch status unknown

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Confirm the affected product and version against the source evidence above.

Restrict access to internet-facing services and apply network segmentation.

Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.

Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-49840 is associated with the following CWEs:

CWE-20: Improper Input Validation CWE-122: Common Weakness Enumeration Entry CWE-122 CWE-195: Common Weakness Enumeration Entry CWE-195 CWE-787: Out-of-bounds Write

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-49840 weaknesses.

CAPEC-66: SQL Injection CAPEC-126: Path Traversal CAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden

PermissionsGerekmiyor

UserGerekmiyor

Official Sources and Advisories

https://github.com/signalwire/freeswitch/releases/tag/v1.11.1nvd https://github.com/signalwire/freeswitch/security/advisories/GHSA-g597-9fgg-ghg9nvd

CVSS Vector Radar Chart

9.1 / 10

Vulnerability Scoring Details

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone required

User InteractionNone required

Confidentiality (Gizlilik)Low

Integrity (Bütünlük)None

Availability (Erişilebilirlik)High

Yama durumu bilinmiyor

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Follow the vendor

freeswitch

Weakness Type (CWE & CAPEC)

CWE-20 CWE-122 CWE-195 CWE-787

Similar Vulnerabilities

6.9

CVE-2026-110658

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