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Fencer Intel
high 8.2

CVE-2026-116783 json

FreeSWITCH mod_spandsp: out-of-bounds write parsing UDPTL error-recovery data

published 4d ago modified 3h ago also EUVD-2026-117759

cvss
8.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits
0
none known

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 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.

Patch / fix

Is CVE-2026-116783 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
3h ago

Exploit prediction

0.62% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

Affected products

  • signalwire freeswitch

Classification

Weakness
  • CWE-129 Improper Validation of Array Index
  • CWE-787 Out-of-bounds Write

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.