OpenSIPS: Denial of Service in SDP bandwidth parsing via QoS SDP cloning
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-476.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA opensips (OpenSIPS) Fixed in 3.6.6, 4.0.0-rc1
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2026-46334
References
More OpenSIPS vulnerabilities
- TI-2026-33290 OpenSIPS: Stack Buffer Overflow in sip_to_json() Header Name Copy CVSS 3.1CRITICAL 9.8
- TI-2026-33289 OpenSIPS: Global Buffer Overflow in construct_uri CVSS 3.1CRITICAL 9.1
- TI-2026-32940 OpenSIPS: Buffer Overflow in Base64 Encode Transformation CVSS 3.1CRITICAL 9.1
- TI-2026-33544 OpenSIPS: Denial of Service in watcherinfo XML generation from oversized watcher URI CVSS 4.0HIGH 8.7
- TI-2026-32931 OpenSIPS: Denial of service in presence.handle_publish() from unchecked Content-Type state CVSS 4.0HIGH 8.7
- TI-2026-32942 OpenSIPS: SIP Message Smuggling via TCP Content-Length Integer Overflow CVSS 3.1HIGH 7.5
Sources
- CVE-2026-46334 · CVE Program
- CVE-2026-46334 · NVD
- FIRST EPSS
- CVE-2026-46334 · Red Hat security data · CC BY 4.0
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