# CVE-2026-75939: Openshift/oc-mirror: release signature verification: openpgp signatureerror checked before signed body is consumed

> Attackers can bypass PGP signature verification in oc-mirror to inject malicious payloads into disconnected registries, compromising deployment integrity.

- **Severity:** High 7.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Sep 2026
- **Updated:** 15 Oct 2026
- **Also known as:** GHSA-vhqx-cfmx-mjq9

## What is CVE-2026-75939?

CVE-2026-75939 is a high-severity vulnerability in Red Hat OpenShift Container Platform 4, published on 21 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw was found in openshift/oc-mirror. The tool incorrectly verifies PGP (Pretty Good Privacy) release image signatures by checking for signature errors before the entire signed body is processed, leading to a bypass of the signature verification. A remote attacker, by intercepting or manipulating network traffic to the signature endpoint, could exploit this to craft a PGP message with a valid Red Hat release key ID but a forged signature. This enables the `oc-mirror` tool to accept and mirror a malicious release payload into a disconnected registry, potentially compromising the integrity of software deployments.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2026-75939?


## How do I fix CVE-2026-75939?

No fix has been published for CVE-2026-75939 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-75939 being exploited?

There is no known exploitation of CVE-2026-75939 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-75939 and fix it if it is affected.

What it is: CVE-2026-75939 is a high-severity vulnerability in Red Hat OpenShift Container Platform 4, published on 21 Sep 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-2026-75939 in the wild and no public exploit code.

Affected product: Red Hat OpenShift Container Platform 4. 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-2026-75939/ (Markdown: https://insights.sbomify.com/CVE-2026-75939/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-75939
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-75939
- OSV: https://osv.dev/vulnerability/CVE-2026-75939

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-75939/
Summaries are generated and may contain mistakes; the official description above is the record.