CVE-2026-49840

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Source
https://cve.org/CVERecord?id=CVE-2026-49840
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49840.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-49840
Aliases
  • GHSA-g597-9fgg-ghg9
Published
2026-06-09T16:00:56.687Z
Modified
2026-07-08T08:12:25.974299Z
Severity
  • 9.1 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H CVSS Calculator
Summary
FreeSWITCH: Pre-authentication heap buffer overflow in libesl `Content-Length` parsing
Details

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, eslrecvevent() 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.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49840.json",
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-122",
        "CWE-195",
        "CWE-20",
        "CWE-787"
    ]
}
References

Affected packages

Git / github.com/signalwire/freeswitch

Affected ranges

Type
GIT
Repo
https://github.com/signalwire/freeswitch
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
c2c59645f6911a76589e5008c4d73349ded44b65
Database specific 
{
    "source": [
        "AFFECTED_FIELD",
        "CPE_RANGE",
        "REFERENCES"
    ],
    "cpe": "cpe:2.3:a:freeswitch:freeswitch:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "1.11.1"
        }
    ]
}

Affected versions

Other
git2svn-syncpoint-master
v.*
v.1.3.12
v.15.9
v0.*
v0.0.1
v1.*
v1.10.0
v1.10.1
v1.10.10
v1.10.11
v1.10.12
v1.10.2
v1.10.3
v1.10.4
v1.10.5
v1.10.6
v1.10.7
v1.10.8
v1.10.9
v1.11.0
v1.2-rc1
v1.2-rc2
v1.3.0
v1.3.1
v1.3.10
v1.3.11
v1.3.12
v1.3.13
v1.3.14
v1.3.15
v1.3.16
v1.3.17-final
v1.3.2
v1.3.3
v1.3.4
v1.3.5
v1.3.6
v1.3.7
v1.3.8
v1.3.9
v1.5.0
v1.5.1
v1.5.10
v1.5.12
v1.5.13
v1.5.14
v1.5.2
v1.5.5
v1.5.8
v1.5.final
v1.6.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49840.json"