FKIE_CVE-2026-49840

Vulnerability from fkie_nvd - Published: 2026-06-09 17:17 - Updated: 2026-06-10 15:06
Severity
9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Summary
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.
References
security-advisories@github.comhttps://github.com/signalwire/freeswitch/releases/tag/v1.11.1Release Notes
security-advisories@github.comhttps://github.com/signalwire/freeswitch/security/advisories/GHSA-g597-9fgg-ghg9Third Party Advisory
Impacted products
Vendor Product Version
freeswitch freeswitch *
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:freeswitch:freeswitch:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "E8AED0D0-D5A1-4AA1-9CAE-13830B74CAC5",
              "versionEndExcluding": "1.11.1",
              "vulnerable": true
            }
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          "negate": false,
          "operator": "OR"
        }
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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "id": "CVE-2026-49840",
  "lastModified": "2026-06-10T15:06:24.257",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-06-09T17:17:47.703",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Release Notes"
      ],
      "url": "https://github.com/signalwire/freeswitch/releases/tag/v1.11.1"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
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    }
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  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-20"
        },
        {
          "lang": "en",
          "value": "CWE-122"
        },
        {
          "lang": "en",
          "value": "CWE-195"
        },
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}


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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
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