# CVE-2026-3136: Google Cloud Build Comment Control Bypass

> A remote attacker can execute arbitrary code in the build environment due to improper authorization in GitHub Trigger Comment Control.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/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:** 3 Mar 2026
- **Updated:** 4 Mar 2026
- **Also known as:** GHSA-p8rp-xfq6-8f8m

## What is CVE-2026-3136?

CVE-2026-3136 is a high-severity missing authorization vulnerability in Google Cloud Cloud Build, published on 3 Mar 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

An improper authorization vulnerability in GitHub Trigger Comment Control in Google Cloud Build prior to 2026-1-26 allows a remote attacker to execute arbitrary code in the build environment.

This vulnerability was patched on 26 January 2026, and no customer action is needed.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-3136?

It affects 1 product.


Products: Google Cloud Build.

## How do I fix CVE-2026-3136?

No fix has been published for CVE-2026-3136 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-3136 being exploited?

There is no known exploitation of CVE-2026-3136 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3136 and fix it if it is affected.

What it is: CVE-2026-3136 is a high-severity missing authorization vulnerability in Google Cloud Cloud Build, published on 3 Mar 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-2026-3136 in the wild and no public exploit code.

Affected product: Google Cloud Cloud Build. 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-2026-3136/ (Markdown: https://insights.sbomify.com/CVE-2026-3136/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3136
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3136
- OSV: https://osv.dev/vulnerability/CVE-2026-3136

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3136/
Summaries are generated and may contain mistakes; the official description above is the record.