# CVE-2026-6874: ericc-ch copilot-api Header token dns rebinding

> Remote attackers can exploit DNS rebinding via the Host header in copilot-api to bypass security controls and access internal resources.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Apr 2026
- **Updated:** 23 Apr 2026
- **Also known as:** GHSA-3vr4-cvmg-7fx4

## What is CVE-2026-6874?

CVE-2026-6874 is a medium-severity server-side request forgery vulnerability in ericc-ch copilot-api, published on 22 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was determined in ericc-ch copilot-api up to 0.7.0. This impacts an unknown function of the file /token of the component Header Handler. Executing a manipulation of the argument Host can lead to reliance on reverse dns resolution. The attack may be performed from remote. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-350 (Reliance on Reverse DNS Resolution for a Security-Critical Action)

## Which versions are affected by CVE-2026-6874?

2 open source packages ship an affected version, including copilot-api.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `copilot-api` | npm | All versions to 0.7.0 | None |
| `copilot-api` | npm | All versions to 0.7.0 | None |

## How do I fix CVE-2026-6874?

No fix has been published for CVE-2026-6874 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-6874 being exploited?

There is no known exploitation of CVE-2026-6874 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-6874 and fix it if it is affected.

What it is: CVE-2026-6874 is a medium-severity server-side request forgery vulnerability in ericc-ch copilot-api, published on 22 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-6874 in the wild and no public exploit code.

Affected packages and fixed versions:
- copilot-api (npm): affected all versions up to 0.7.0; no fix listed
- copilot-api (npm): affected all versions up to 0.7.0; no fix listed

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-2026-6874/ (Markdown: https://insights.sbomify.com/CVE-2026-6874/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-6874
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-6874
- OSV: https://osv.dev/vulnerability/CVE-2026-6874

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-6874/
Summaries are generated and may contain mistakes; the official description above is the record.