Is CVE-2026-87803 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-87803 being exploited in the wild.

How severe is CVE-2026-87803?

High severity, with a CVSS score of 7.1, published 10 September 2026.

Is there a fix for CVE-2026-87803?

A patch was published on 2026-08-25: Fix merged in PR #7868 with allow-list validation approach Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-87803 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-87803?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-87803: Countly Server DBViewer authorization bypass in aggregation pipeline

CVE-2026-87803 · Severity: high · CVSS 7.1 · Published 2026-09-10

Countly Server's DBViewer component allows unauthorized users to read sensitive data by bypassing access controls in the database query aggregation endpoint. An attacker with read permissions can exploit flawed validation logic to access restricted collections and steal sensitive information such as password-reset tokens, potentially enabling account takeover.

Quick answers

Is CVE-2026-87803 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-87803 being exploited in the wild.
How severe is CVE-2026-87803?: High severity, with a CVSS score of 7.1, published 10 September 2026.
Which products and versions are affected?: Countly Server <7868.
Is there a fix for CVE-2026-87803?: A patch was published on 2026-08-25: Fix merged in PR #7868 with allow-list validation approach Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-87803 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-87803?: Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability exists in the /o/db aggregation endpoint, which parses user-controlled JSON and validates it through a stage sanitizer. The sanitizer incorrectly identifies sub-pipelines by checking if all elements contain keys from a hardcoded KNOWN_STAGE_OPERATORS set. An attacker can inject an undocumented MongoDB-internal operator such as $_internalInhibitOptimization to trick the sanitizer into misclassifying the branch as a generic array, bypassing stage-level stripping. This allows injection of forbidden operators like $lookup inside $facet sub-pipelines to perform cross-collection joins and access restricted data. The vulnerability requires DBViewer read permission but does not require admin privileges. A fix was merged via an allow-list validation approach in August 2026.

Affected products

Countly Server <7868

Timeline

2026-09-10: disclosed: CVE-2026-87803 published
2026-08-25: patched: Fix merged in PR #7868 with allow-list validation approach

References

https://github.com/Countly/countly-server/pull/7868

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