# CVE-2026-1698: HTTP Host header vulnerability in WebClient and WebScheduler web apps

> Remote attackers can manipulate server-side behavior via HTTP Host header injection in PcVue web applications, potentially bypassing security controls.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:L/SI:L/SA:N/AU:Y/R:U/RE:M/U:Clear`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 26 Feb 2026
- **Updated:** 26 Mar 2026
- **Also known as:** GHSA-35x7-r658-wx7f

## What is CVE-2026-1698?

CVE-2026-1698 is a medium-severity vulnerability in arcinfo PcVue, published on 26 Feb 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A HTTP Host header attack vulnerability affects WebClient and the WebScheduler web apps of PcVue in version 15.0.0 through 16.3.3 included, allowing a remote attacker to inject harmful payloads that manipulate server-side behavior.

This vulnerability only affects the endpoints /Authentication/ExternalLogin, /Authentication/AuthorizationCodeCallback and /Authentication/Logout
of the WebClient and WebScheduler web apps.

Weakness: CWE-644 (Improper Neutralization of HTTP Headers for Scripting Syntax)

## Which versions are affected by CVE-2026-1698?

It affects 1 product.


Products: Arcinfo Pcvue.

## How do I fix CVE-2026-1698?

No fix has been published for CVE-2026-1698 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-1698 being exploited?

There is no known exploitation of CVE-2026-1698 in the wild and no public exploit code.

## Other vulnerabilities in arcinfo PcVue

- [CVE-2020-26867](https://insights.sbomify.com/CVE-2020-26867/): ARC Informatique PcVue Deserialization of Untrusted Data (critical 9.8)
- [CVE-2026-14868](https://insights.sbomify.com/CVE-2026-14868/): Weak encryption mechanism for User directory (high 8.4)
- [CVE-2020-26868](https://insights.sbomify.com/CVE-2020-26868/): ARC Informatique PcVue Access to Critical Private Variable via Public Method (high 7.5)
- [CVE-2020-26869](https://insights.sbomify.com/CVE-2020-26869/): ARC Informatique PcVue Exposure of Sensitive Information to an Unauthorized Actor (high 7.5)
- [CVE-2026-14867](https://insights.sbomify.com/CVE-2026-14867/): Insecure password storage in User directory (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-1698 and fix it if it is affected.

What it is: CVE-2026-1698 is a medium-severity vulnerability in arcinfo PcVue, published on 26 Feb 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-1698 in the wild and no public exploit code.

Affected product: arcinfo PcVue. 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-2026-1698/ (Markdown: https://insights.sbomify.com/CVE-2026-1698/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-1698
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-1698
- OSV: https://osv.dev/vulnerability/CVE-2026-1698

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-1698/
Summaries are generated and may contain mistakes; the official description above is the record.