CVE-2026-42316 | KQL injection via kusto.tables.topics.mapping in kafka-sink-azure-kusto

kafka-sink-azure-kusto Kafka Connect plugin is the official Microsoft sink for Azure Data Explorer (Kusto). Prior to 5.2.3, kafka-sink-azure-kusto did not sanitize user-controlled values inside the kusto.tables.topics.mapping configuration. The db, table, mapping, and format fields of each mapping entry were interpolated directly into KQL management/query commands via String.formatted(...) (e.g., FETCH_TABLE_COMMAND.formatted(table) → "<table> | count", FETCH_TABLE_MAPPING_COMMAND.formatted(table, format, mapping) → ".show table <table> ingestion <format> mapping '<mapping>'"). An actor able to influence the connector configuration (for example, someone with permissions to submit or edit Kafka Connect connector configs) could embed KQL metacharacters (;, |, ') to execute arbitrary management commands in the context of the connector's service principal — enabling schema enumeration/modification, ingestion-mapping tampering, or changes to streaming/retention policies on the target Azure Data Explorer database. This is a tampering vulnerability. Exploitation requires privileged access to the connector configuration; no end-user interaction or Kafka record payload is involved. This vulnerability is fixed in 5.2.3.

Published: 2026-05-11 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-42316 is rated Low Risk (35.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.34%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-42316

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.02% 0.34% +0.32%
2 2026-05-12 0.02%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-42316

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
1.2 5.2 [email protected]

Weakness enumeration for CVE-2026-42316

Affected software / configurations for CVE-2026-42316

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-42316

cvelogic Threat Intelligence