Stack buffer overflow in FreeSWITCH mod_xml_rpc HTTP authentication
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.
Summary
FreeSWITCH before 1.11.2 has a stack buffer overflow in http_directory_auth() in mod_xml_rpc. The function encodes a user@domain:password credential into an 80-byte buffer without an output length limit, so a configured credential longer than 57 characters overflows the stack before the HTTP Basic password is compared. An unauthenticated client only needs to name an existing directory user on an exposed mod_xml_rpc HTTP listener, which the stock configuration does not load. The overflow can crash FreeSWITCH and end all active calls, and remote code execution has not been demonstrated.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
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, http_directory_auth() rebuilt an expected user@domain:password credential and base64-encoded it into an 80-byte buffer using an encoder without an output-length argument. A configured credential longer than 57 characters overflowed the stack before the supplied HTTP Basic password was compared. An unauthenticated client only needed to name an existing directory user on an exposed mod_xml_rpc HTTP listener; the module is built but not loaded by the stock configuration. The overflow can corrupt the stack and crash FreeSWITCH, ending every active call, although the overrun bytes come from the configured credential and remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| signalwire | freeswitch | before 1.11.2 | 1.11.2 | Patch available | CNA |
- freeswitch Vendorsignalwire Affected before 1.11.2 Fixed in 1.11.2 Patch available CNA
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:freeswitch:freeswitch:*:*:*:*:*:*:*:* | — | — | freeswitch |
- cpe:2.3:a:freeswitch:freeswitch:*:*:*:*:*:*:*:* Versions — — ·freeswitch
Remediation
Upgrade FreeSWITCH to version 1.11.2, which fixes the issue.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA freeswitch (signalwire) Fixed in 1.11.2
Vendor assessments
Timeline
- 2026-11-05 Threatist record created from CVE-2026-116570
- 2026-11-06 Affected versions changed · Red Hat
- 2026-11-06 CVSS score added · Red Hat
- 2026-11-07 Priority changed: MEDIUM → LOW
References
More signalwire vulnerabilities
- TI-2023-08915 heap-over-flow in stun_parse_attribute in sofia-sip CVSS 3.1CRITICAL 9.8
- TI-2022-13049 Heap-based Buffer Overflow and Out-of-bounds Write in Sofia-SIP CVSS 3.1CRITICAL 9.8
- TI-2023-28097 FreeSWITCH susceptible to Denial of Service via DTLS Hello packets during call initiation CVSS 3.1HIGH 7.5
- TI-2023-20909 Resource allocation without limits in signalwire freeswitch CVSS 3.1HIGH 7.5
- TI-2023-20908 FreeSWITCH allows remote users to trigger out of bounds write by offering an ICE candidate with unknown component ID CVSS 3.1HIGH 7.5
- TI-2023-15601 heap-over-flow and integer-overflow in sofia-sip CVSS 3.1HIGH 7.5
Sources
- CVE-2026-116570 · CVE Program
- CVE-2026-116570 · NVD
- FIRST EPSS
- CVE-2026-116570 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences