CVE-2026-82059: mongodb Reachable Assertion

Vulnerability summary

CVE-2026-82059 is a medium (CVSS 6.5) Reachable Assertion vulnerability in mongodb. EPSS estimates a 0.37% chance of exploitation in the next 30 days, higher than 29.3% of scored vulnerabilities.

Timeline

1. 08-09-2026
   PublishedVulnerability first disclosed.
2. 08-09-2026
   Last modifiedVulnerability information updated.

Description

An internal aggregation expression in MongoDB Server was incorrectly registered as accessible to any authenticated user rather than being restricted to internal cluster operations. By crafting a malformed index specification within this expression, an authenticated user with read-only privileges could trigger an assertion failure in the index key generation code path. In certain build configurations, this assertion failure results in termination of the mongod process, causing a denial of service to all connected clients.

• CWE-617Reachable AssertionThe product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.