# CVE-2026-4374: XML external entity in Connext Professional

> Attackers can exploit XML External Entity flaws in RTI Connext Professional services to read sensitive data or cause denial of service.

- **Severity:** High 8.8 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/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:** 1 Apr 2026
- **Updated:** 22 Sep 2026
- **Also known as:** GHSA-f5w8-q66w-xp9m

## What is CVE-2026-4374?

CVE-2026-4374 is a high-severity vulnerability in RTI Connext Professional, published on 1 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Improper Restriction of XML External Entity Reference vulnerability in RTI Connext Professional (Recording Service,Routing Service,Queueing Service,Cloud Discovery Service,Observability Collector) allows Serialized Data External Linking, Data Serialization External Entities Blowup. This issue affects Connext Professional: from 7.4.0 before 7.7.0, from 7.0.0 before 7.3.1.1, from 6.1.0 before 6.1.2.34, from 6.0.0 before 6.0.*, from 5.3.0 before 5.3.*.

Weakness: CWE-611 (Improper Restriction of XML External Entity Reference)

## Which versions are affected by CVE-2026-4374?

It affects 1 product.


Products: Rti Connext Professional.

## How do I fix CVE-2026-4374?

No fix has been published for CVE-2026-4374 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-4374 being exploited?

There is no known exploitation of CVE-2026-4374 in the wild and no public exploit code.

## Other vulnerabilities in RTI Connext Professional

- [CVE-2026-2467](https://insights.sbomify.com/CVE-2026-2467/): Memory corruption in Connext Professional (critical 9.2)
- [CVE-2026-3894](https://insights.sbomify.com/CVE-2026-3894/): Out-of-bounds Read vulnerability in RTI Connext Professional (Core Libraries) allows Overread Buffers. (critical 9.2)
- [CVE-2024-52057](https://insights.sbomify.com/CVE-2024-52057/): SQL injection in Connext Professional (critical 9.1)
- [CVE-2026-7300](https://insights.sbomify.com/CVE-2026-7300/): Memory corruption in Connext Professional (high 8.8)
- [CVE-2025-14543](https://insights.sbomify.com/CVE-2025-14543/): XML external entity in Connext Professional (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-4374 and fix it if it is affected.

What it is: CVE-2026-4374 is a high-severity vulnerability in RTI Connext Professional, published on 1 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-4374 in the wild and no public exploit code.

Affected product: RTI Connext Professional. 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-2026-4374/ (Markdown: https://insights.sbomify.com/CVE-2026-4374/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-4374
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4374
- OSV: https://osv.dev/vulnerability/CVE-2026-4374

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-4374/
Summaries are generated and may contain mistakes; the official description above is the record.