# CVE-2026-100730: Grid Protection Alliance openPDC and openHistorian Deserialization of Untrusted Data

> An attacker can trigger unsafe deserialization in openPDC and openHistorian, potentially achieving remote code execution under the service account privileges.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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:** 9 Oct 2026
- **Updated:** 11 Oct 2026
- **Also known as:** GHSA-g2gc-jv32-q89f

## What is CVE-2026-100730?

CVE-2026-100730 is a critical unsafe deserialization vulnerability in Grid Protection Alliance openHistorian, published on 9 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A service console interface on openPDC and openHistorian deserializes a client-supplied data structure. On systems using Windows Authentication, an attacker must already be authenticated to reach this function; on systems without Windows Authentication, this is reachable by an unauthenticated network attacker. This allows an attacker to trigger deserialization of an arbitrary object graph, which could allow remote code execution under the privileges of the affected service account.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-100730?


## How do I fix CVE-2026-100730?

No fix has been published for CVE-2026-100730 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-100730 being exploited?

There is no known exploitation of CVE-2026-100730 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-100730 and fix it if it is affected.

What it is: CVE-2026-100730 is a critical unsafe deserialization vulnerability in Grid Protection Alliance openHistorian, published on 9 Oct 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-2026-100730 in the wild and no public exploit code.

Affected product: Grid Protection Alliance openHistorian. 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-2026-100730/ (Markdown: https://insights.sbomify.com/CVE-2026-100730/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-100730
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-100730
- OSV: https://osv.dev/vulnerability/CVE-2026-100730

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-100730/
Summaries are generated and may contain mistakes; the official description above is the record.