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CVE.org (no NVD analysis yet)· CNA GitHub_M

CVE-2026-116567: FreeSWITCH: Pre-authentication stack buffer overflow in mod_rtmp control-message handling

Noroxi assessment

Priority: Monitor (action score 30/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.43% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: signalwire freeswitch 1.11.2.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to signalwire freeswitch 1.11.2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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 1.11.2, rtmp_handle_control() rendered an RTMP user-control message into a 200-byte stack buffer using an unbounded sprintf loop controlled by the wire message length. A body of roughly 70 bytes or more overflowed the stack before any RTMP login, because the handshake authenticates neither side. The flaw affects deployments that build and load mod_rtmp, which is disabled in the stock build and configuration but commonly exposes a listener on TCP port 1935 when enabled. One unauthenticated message can crash FreeSWITCH and end every active call; the constrained ASCII hex output has not yielded control-flow hijacking. This issue is fixed in version 1.11.2.

HighCVSS 7.5 · v3.1—Proof of concept Fix available
Published
Nov 5, 2026
Updated
Nov 9, 2026
EPSS
0.4% · 37th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
7.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-116567

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • signalwire freeswitch

    • < 1.11.2affected

Same product

signalwire: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-116790FreeSWITCH: Inbound ICE connectivity checks are accepted without verifying STUN MESSAGE-INTEGRITY
    36Monitor
  • CVE-2026-116785FreeSWITCH: Pre-authentication heap out-of-bounds write in mod_xml_rpc WebSocket frame length handling
    36Monitor
  • CVE-2026-116786FreeSWITCH: Channel-variable injection via SIP REFER leads to command execution in mod_sofia
    35Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-116574Nov 5, 2026 · FreeSWITCH: Off-by-one heap write in core XML serialization of four-byte UTF-8 sequences
    23Monitor
  • ← EarlierCVE-2026-115928Nov 5, 2026 · FreeSWITCH: Stack buffer overflow parsing the SDP a=crypto key material on inbound calls
    30Monitor
  • Later →CVE-2026-116568Nov 5, 2026 · FreeSWITCH: Out-of-bounds read in mod_rtmp H.264 video message parsing
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
signalwire freeswitch1.11.2 · descriptionVendor (CNA)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:02026-11-09

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. First PoC+3 d
  4. TodayNov 10, 2026+5 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-1159280 days apartFreeSWITCH: Stack buffer overflow parsing the SDP a=crypto key material on inbound calls
    30Monitor
  • CVE-2026-1165700 days apartFreeSWITCH: Pre-authentication stack buffer overflow in mod_xml_rpc HTTP directory authentication
    30Monitor
  • CVE-2026-1165720 days apartFreeSWITCH mod_sofia: stack buffer overflow from an over-long SIP Contact display-name
    26Monitor
  • CVE-2026-1165730 days apartFreeSWITCH mod_sofia: stack buffer overflow from an over-long SIP To-header user
    26Monitor
  • CVE-2026-1165710 days apartFreeSWITCH: Stack buffer overflow in mod_rtmp AVC sequence-header construction
    23Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-121 · Stack-based Buffer Overflow

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Exploit maturitynone → poc
  2. SSVC exploitation— → none
  3. Exploit maturity— → none
  4. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records