freeswitch: Out-of-bounds Read
CVE-2026-116568 is a high-severity out-of-bounds read vulnerability in freeswitch from Signalwire, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected freeswitch versions: < 1.11.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.53% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of freeswitch you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Signalwire | freeswitch | < 1.11.2 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (github.com).
Official description
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_rtmp2rtpH264() trusted the length prefix of each inbound H.264 NAL unit without checking it against the bytes remaining in the RTMP message. An oversized declared unit underflowed the unsigned remaining-byte counter and advanced the parser beyond its receive buffer, where the next length-prefix read could crash the process. The flaw affects deployments that build and load mod_rtmp and accept video call sessions, commonly on TCP port 1935; placing the call requires a directory login where auth-calls is true, while no credentials are required where auth-calls is absent or false. A remote client can terminate FreeSWITCH and every active call, but the defect supplies no write primitive and memory disclosure has not been demonstrated. This issue is fixed in version 1.11.2.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
Other vulnerabilities in freeswitch
- 9.1 Critical severity
- 7.4 High severity
- 8.2 High severity
- 7.5 High severity
- 8.8 High severity
- 9.1 Critical severity
Recent Out-of-bounds Read vulnerabilities
- 8.2 High severity
- 7.5 High severity
- 8.2 High severity
- 8.2 High severity
- 7.5 High severity
- 7.5 High severity
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