OpenSIPS up to 3.6.5 SDP bandwidth-line parsing logic resource consumption

Summaryinfo

A vulnerability labeled as critical has been found in OpenSIPS up to 3.6.5. This vulnerability affects unknown code of the component SDP bandwidth-line parsing logic. The manipulation results in resource consumption. This vulnerability is cataloged as CVE-2026-46334. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as critical, was found in OpenSIPS up to 3.6.5. Affected is an unknown part of the component SDP bandwidth-line parsing logic. The manipulation with an unknown input leads to a resource consumption vulnerability. CWE is classifying the issue as CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. This is going to have an impact on availability. CVE summarizes:

OpenSIPS is a Session Initiation Protocol (SIP) server implementation. Versions prior to 3.6.6 and 4.0.0-rc1 contain a denial of service vulnerability in the SDP bandwidth-line parsing logic. A SIP request with Content-Type: application/sdp and a malformed session-level SDP bandwidth line missing the required colon delimiter can corrupt parsed SDP bandwidth metadata. When a route or module subsequently clones the corrupted SDP state, as occurs with dialog and QoS processing, the OpenSIPS worker process crashes. An unauthenticated remote attacker can therefore trigger a crash in any configuration whose routing script parses attacker-controlled SDP and applies dialog/QoS processing. This issue has been fixed in versions 3.6.6 and 4.0.0-rc1.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-46334 since 05/13/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1499.

Upgrading to version 3.6.6 or 4.0.0-rc1 eliminates this vulnerability.

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Productinfo

Name

• OpenSIPS

Version

• 3.6.0
• 3.6.1
• 3.6.2
• 3.6.3
• 3.6.4
• 3.6.5

Website

• Product: https://github.com/OpenSIPS/opensips/

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