# CVE-2026-87803: Missing authorization in countly-server

> Non-admin users can bypass aggregation sanitization to read restricted data, including password-reset tokens, leading to account takeover.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Sep 2026
- **Updated:** 10 Sep 2026
- **Also known as:** GHSA-3m7r-f729-ggmf

## What is CVE-2026-87803?

CVE-2026-87803 is a high-severity missing authorization vulnerability in countly-server, published on 10 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An authorization bypass vulnerability exists in the Countly Server DBViewer due to flawed sub-pipeline detection in the aggregation stage sanitizer. The /o/db aggregation endpoint parses user-controlled aggregation JSON and passes it through a stage sanitizer that determines whether a nested array is a sub-pipeline by checking if every element contains a key present in a hardcoded KNOWN_STAGE_OPERATORS set. If any element contains an unrecognized stage key, such as the undocumented MongoDB-internal $_internalInhibitOptimization, the sanitizer misclassifies the entire branch as a generic array and skips stage-level stripping for all sibling stages. This allows a non-admin user with DBViewer read permission to inject forbidden operators like $lookup inside $facet sub-pipelines, performing cross-collection joins into restricted collections. This leads to unauthorized read access to sensitive data including password-reset tokens (prid), enabling account takeover.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-87803?


## How do I fix CVE-2026-87803?

No fix has been published for CVE-2026-87803 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-87803 being exploited?

There is no known exploitation of CVE-2026-87803 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-87803 and fix it if it is affected.

What it is: CVE-2026-87803 is a high-severity missing authorization vulnerability in countly-server, published on 10 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-87803 in the wild and no public exploit code.

Affected product: countly-server. 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-2026-87803/ (Markdown: https://insights.sbomify.com/CVE-2026-87803/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-87803
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-87803
- OSV: https://osv.dev/vulnerability/CVE-2026-87803

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-87803/
Summaries are generated and may contain mistakes; the official description above is the record.