Unauthenticated process crash via undersized STUN attributes
Published Jun 9, 2026 · Updated Jun 9, 2026
Out-of-bounds memory access in FreeSWITCH before 1.11.0 allows remote attackers to crash the process via a crafted STUN packet. The switch_stun_packet_parse() function casts undersized attribute payloads to address or 32-bit structures and then byte-swaps fields without confirming that the payload can hold the selected type. The flaw is reachable only on an active ICE-enabled media leg, where one unauthenticated UDP datagram can terminate FreeSWITCH and drop every concurrent session; code execution has not been demonstrated.
Summary
What happened
Out-of-bounds memory access in FreeSWITCH before 1.11.0 allows remote attackers to crash the process via a crafted STUN packet. The switch_stun_packet_parse() function casts undersized attribute payloads to address or 32-bit structures and then byte-swaps fields without confirming that the payload can hold the selected type. The flaw is reachable only on an active ICE-enabled media leg, where one unauthenticated UDP datagram can terminate FreeSWITCH and drop every concurrent session; code execution has not been demonstrated.
The record
- CVE
- CVE-2026-49475
- Published
- Jun 9, 2026
- Updated
- Jun 9, 2026
- Vendor
- SignalWire
- Product
- FreeSWITCH
- Classifications
- CWE-125, CWE-20, CWE-787, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 9, 2026CVE publishedPublication date reported by the CVE source.
- Jun 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 1.11.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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