# CVE-2026-45084: OpenSIPS: Denial of service in presence.handle_publish() from unchecked Content-Type state

> Remote attackers can crash OpenSIPS via crafted SIP PUBLISH requests when sphere checks are enabled, requiring an upgrade to patched versions.

- **Severity:** High 8.7 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Aug 2026
- **Updated:** 5 Aug 2026
- **Also known as:** GHSA-h3ww-hchh-x2g9, UBUNTU-CVE-2026-45084

## What is CVE-2026-45084?

CVE-2026-45084 is a high-severity vulnerability in opensips, published on 4 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

OpenSIPS is a Session Initiation Protocol (SIP) server implementation. Versions 3.4.0 through 3.6.5 contain a denial of service vulnerability in the presence module. When the presence module's handle_publish() function processes a SIP PUBLISH request with an Event: presence header and a message body while the configuration option enable_sphere_check=1 is set, it invokes the get_content_type() macro without first calling parse_content_type_hdr(), causing it to dereference uninitialized or NULL Content-Type parsing state and crash. If a Content-Type header is present but unparsed, msg->content_type->parsed is NULL and is dereferenced as a content_t pointer; if the request lacks a Content-Type header entirely, msg->content_type itself is NULL, and both cases lead to a crash. A remote attacker can therefore cause a denial of service against an affected instance with a single PUBLISH request over UDP or TCP, using either a valid Content-Type: application/pidf+xml request or one with the header removed, and the vulnerable code path itself does not enforce authentication (though a deployment's routing configuration may require it before this route is reached). The issue has been fixed in version 3.6.6 and 4.0.0-rc1.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-45084?


## How do I fix CVE-2026-45084?

No fix has been published for CVE-2026-45084 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-45084 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-45084 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45084 and fix it if it is affected.

What it is: CVE-2026-45084 is a high-severity vulnerability in opensips, published on 4 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-45084 exists.

Affected product: opensips. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-45084/ (Markdown: https://insights.sbomify.com/CVE-2026-45084/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45084
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45084
- OSV: https://osv.dev/vulnerability/CVE-2026-45084

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45084/
Summaries are generated and may contain mistakes; the official description above is the record.