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FreeswitchApplication

CVE-2026-49475

HIGH · 7.5 CVSS v3.1 Published 2026-06-09
Fix available
A fix is available. Upgrade to 1.11.0 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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 1.11.0, a STUN packet whose declared attribute length is shorter than the structure the parser casts to causes the parser to read and write past the end of the attribute, producing an out-of-bounds memory access on the per-leg media buffer. This issue has been patched in version 1.11.0.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

FreeSWITCH versions prior to 1.11.0 contain a buffer over-read/write vulnerability in the STUN packet parser. When processing STUN packets, the parser does not validate that the declared attribute length is sufficient for the structure it casts to, causing it to read and write past the end of the attribute into the per-leg media buffer.

MitigationUpgrade FreeSWITCH to version 1.11.0 or later. If immediate patching is not feasible, filter or block external STUN traffic at the network perimeter as a temporary compensating control.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FreeswitchApplication
Affected:< 1.11.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine installed FreeSWITCH version
    Run 'freeswitch -version' or 'fs_cli -v' to display the version number. Alternatively, check the output of 'show version' from the fs_cli console.
    Affected if The displayed version is any version prior to 1.11.0 (for example, 1.10.x, 1.8.x, or earlier).
  2. Identify if STUN is configured in SIP profiles
    Examine the SIP profile configuration files (typically in /usr/local/freeswitch/conf/sip_profiles/ or /etc/freeswitch/sip_profiles/) for any 'stun-enabled' or 'stun' settings. Use grep to search: grep -r 'stun' /path/to/sip_profiles/
    Affected if Any SIP profile has 'stun-enabled' set to 'true' or includes a stun server address.
  3. Check for STUN usage in dialplan or XML configurations
    Search configuration files for STUN-related variables: grep -r 'stun' /usr/local/freeswitch/conf/ or /etc/freeswitch/conf/ including dialplan and directory configs.
    Affected if STUN is explicitly referenced in any FreeSWITCH configuration files that are loaded.
  4. Verify STUN traffic reaching FreeSWITCH
    Monitor network traffic on the SIP port (typically 5060) for STUN binding requests (port 3478) or check logs for STUN-related messages. Review /var/log/freeswitch/freeswitch.log for stun or STUN keywords.
    Affected if STUN packets are being received and processed by the FreeSWITCH instance.

You are affected if FreeSWITCH version is below 1.11.0 AND STUN is enabled in any SIP profile or configuration and STUN traffic is being processed.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.11.0 or later
Fixed in 1.11.0
Interim mitigation

Upgrade FreeSWITCH to version 1.11.0 or later. If immediate patching is not feasible, filter or block external STUN traffic at the network perimeter as a temporary compensating control.

Recommended fix High confidence

1.11.0

  1. 1. Backup your current FreeSWITCH configuration and any custom modules
  2. 2. Stop the FreeSWITCH service
  3. 3. Upgrade FreeSWITCH to version 1.11.0 or later using your package manager or compile from source
  4. 4. Verify the installation succeeded
  5. 5. Restart the FreeSWITCH service
  6. 6. Test that STUN functionality and core call flows work correctly
Caveat Review release notes for 1.11.0 for any configuration or API changes; minor version upgrades typically have low breaking change risk

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Freeswitch Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-49475 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data