CVE-2026-87803 (GCVE-0-2026-87803)
Vulnerability from cvelistv5 – Published: 2026-09-10 09:54 – Updated: 2026-09-10 13:17
VLAI
EPSS
VEX
Summary
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.
Severity
7.1 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-10 13:16 UTC
CWE
- CWE-863 - Countly DBViewer authorization bypass via nested aggregation stage poisoning
Assigner
References
1 reference
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Countly | countly-server |
Affected:
0 , < 25.03.53-LTS
(semver)
|
guessed |
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Nomenclature
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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