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.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
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
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.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-87803 being exploited?
There is no known exploitation of CVE-2026-87803 in the wild and no public exploit code.
Sources
Also known as GHSA-3m7r-f729-ggmf.