VulnerabilityPublished 5 Nov 2026

CVE-2026-116781: signalwire freeswitch · Off-by-one Error

Affects signalwire freeswitchSource CVE Database V5

Compare

Not known to be exploited · CVSS 5.3 Medium : upgrade to 1.11.2 when convenient.

Data as of 5 Nov 2026, 19:51 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.1	5.3

Patch: Available – fixed in 1.11.2

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 5 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade signalwire freeswitch to 1.11.2.

Affected software

Product	Affected	Fixed in
signalwirefreeswitch	Affected <1.11.2	Fixed in 1.11.2

AI-suggested

Upgrade FreeSWITCH to version 1.11.2 or later, where this off-by-one error has been fixed. The vulnerability is only exploitable if mod_xml_rpc and its WebSocket endpoint are enabled, which are disabled by default. If these features are not in use, the risk is reduced. No additional mitigation is required beyond applying the official fix.

Description

CVE-2026-116781 is an off-by-one error vulnerability in FreeSWITCH prior to version 1.11.2. The flaw occurs in the ws_read_frame() function when unmasking WebSocket payloads, potentially causing writes up to 14 bytes beyond the receive buffer and a terminating NUL byte one byte out of bounds. This vulnerability is reachable before authentication if mod_xml_rpc and its WebSocket endpoint are enabled, though these features are disabled by default. The out-of-bounds writes remain within the same connection handle's adjacent outbound buffer, and no process crash or cross-session data disclosure has been demonstrated. The issue is fixed in FreeSWITCH version 1.11.2.

Impact

The vulnerability allows an attacker to write up to 14 bytes beyond the allocated receive buffer and one byte out of bounds with a terminating NUL byte. However, these writes are confined within the same connection handle's adjacent outbound buffer, limiting the impact. There is no demonstrated process crash or cross-session data disclosure. The CVSS score is 5.3 (medium severity) with no confidentiality or availability impact, only integrity impact.

CWE-193Off-by-one Error (opens in a new tab)
Base weakness
A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.
Implementation
When copying character arrays or using character manipulation methods, the correct size parameter must be used to account for the null terminator that needs to be added at the end of the array.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-787Out-of-bounds Write (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #5
The product writes data past the end, or before the beginning, of the intended buffer.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 5 Nov 2026, 19:51 UTC

WeaknessesCWE-193, CWE-787

Technical details

References

Community reviews

Related threats