# CVE-2026-93639: A missing authorization vulnerability in Zimbra Collaboration Suite (ZCS) allows a delegated administrator with no explicit administrative g


- **Severity:** High 8.7 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 23 Oct 2026
- **Updated:** 28 Oct 2026
- **Also known as:** GHSA-q3fj-jg2r-pp4p

## What is CVE-2026-93639?

CVE-2026-93639 is a high-severity vulnerability in Zimbra Collaboration Suite, published on 23 Oct 2026. 

### Official description

A missing authorization vulnerability in Zimbra Collaboration Suite (ZCS) allows a delegated administrator with no explicit administrative grants to overwrite global Zimlet configuration through ConfigureZimletRequest. The uploaded configuration can also add an attacker-controlled domain to the proxy allowlist of the default class of service. If a signed-in user in that class opens a crafted /service/proxy URL, Zimbra serves attacker-controlled HTML under its own origin. The resulting JavaScript can read mailbox data and perform authenticated actions as the victim. Exploitation requires a delegated-administrator account and access to the admin SOAP service; the browser compromise additionally requires the victim to open the crafted URL. ZCS 10.1.16 and 10.1.20 are affected.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-93639?


## How do I fix CVE-2026-93639?

No fix has been published for CVE-2026-93639 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-93639 being exploited?

There is no known exploitation of CVE-2026-93639 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93639 and fix it if it is affected.

What it is: CVE-2026-93639 is a high-severity vulnerability in Zimbra Collaboration Suite, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-93639 in the wild and no public exploit code.

Affected product: Zimbra Collaboration Suite. 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-2026-93639/ (Markdown: https://insights.sbomify.com/CVE-2026-93639/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93639
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93639
- OSV: https://osv.dev/vulnerability/CVE-2026-93639

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93639/
Summaries are generated and may contain mistakes; the official description above is the record.