CVE-2026-116783
FreeSWITCH mod_spandsp: out-of-bounds write parsing UDPTL error-recovery data
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, udptl_rx_packet() used a peer-controlled FEC entry count directly to fill five-entry FEC arrays in a mod_spandsp T.38 session. A larger count wrote sender-controlled error-recovery data beyond those arrays and persisted the oversized count for a later reconstruction pass. Any peer able to deliver UDPTL to an established T.38 fax session can reach the parser, including deployments using fax applications or a T.38 gateway. The memory corruption can crash FreeSWITCH and end every active call, although remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.
Fixes and workarounds
Fix
FreeSWITCH (c): GitHub reports patched versions >= 1.11.2. Check the advisory for the affected release branch.
Source: GitHub GHSA-mjp3-3cq2-hxj4Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| freeswitch signalwire |
< 1.11.2 (affected) | CNA: GitHub_M |
FreeSWITCHFreeSWITCH
c |
<= 1.11.1 (affected, GitHub advisory range) | GitHub GHSA-mjp3-3cq2-hxj4 |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 8.2 high |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H | CNA: GitHub_M |
| 3.1 / 8.2 high |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H | NVD: [email protected] |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/signalwire/freeswitch/security/advisories/GHSA-mjp3-3cq2-hxj4CNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/signalwire/freeswitch/commit/b999d2a594f025ac0dd4d7b137635308ef298272CNA: GitHub_M · x_refsource_MISC
- https://github.com/signalwire/freeswitch/releases/tag/v1.11.2CNA: GitHub_M · x_refsource_MISC
- https://github.com/signalwire/freeswitch/commit/b999d2a594f025ac0dd4d7b137635308ef298272[email protected]
- https://github.com/signalwire/freeswitch/releases/tag/v1.11.2[email protected]
- https://github.com/signalwire/freeswitch/security/advisories/GHSA-mjp3-3cq2-hxj4[email protected]
- https://github.com/signalwire/freeswitch/security/advisories/GHSA-mjp3-3cq2-hxj4GitHub Security Advisories · advisory
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