CVE-2026-16651
Received Received - Intake

MySQL Version Comment Parsing Panic in Temporal Server

Publication date: 2026-09-21

Last updated on: 2026-09-21

Assigner: Temporal Technologies Inc.

Description
temporalio/sqlparser can panic when Parse, ParseStrictDDL, or ParseNext processes a MySQL version comment whose contents are empty or consist only of one to five decimal digits. ExtractMysqlComment does not check the -1 result returned by strings.IndexFunc before using it as a slice boundary. The resulting Go runtime panic propagates unless the caller recovers it on the parsing goroutine, so applications that parse attacker-controlled SQL can terminate. Temporal Server exposes the affected parser through ListWorkers. When that API is enabled, an authenticated caller with namespace read permission can submit a malformed query that terminates the receiving Matching process. Repeated requests can sustain a denial of service. The issue affects availability only; no confidentiality or integrity impact was identified.

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Meta Information

Published
2026-09-21
Last Modified
2026-09-21
Generated
2026-09-21
AI Q&A
2026-09-21
EPSS Evaluated
N/A
NVD
CVE-2026-16651
EUVD
EUVD-2026-83891

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
temporal sqlparser *
temporalio sqlparser *
temporalio temporal From 1.29.8 (inc) to 1.31.3 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-129 The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.

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Executive Summary

This vulnerability involves a panic condition in the temporalio/sqlparser library when processing MySQL version comments with empty content or only decimal digits. The parser fails to validate input properly, causing a Go runtime panic that can crash applications parsing attacker-controlled SQL. Temporal Server exposes this parser through the ListWorkers API, allowing authenticated users with namespace read permissions to submit malformed queries that terminate the Matching process, leading to a denial of service.

Detection Guidance

This vulnerability involves a panic in the sqlparser when processing MySQL version comments with empty or numeric-only content. To detect it, monitor for crashes in Temporal Server processes, particularly the Matching service, after parsing SQL queries containing such comments. Check logs for panic messages or unexpected terminations in the Temporal Server logs.

Impact Analysis

If you use Temporal Server with the affected sqlparser version, an attacker with namespace read access could crash the Matching process by submitting a specially crafted query. This would cause repeated service disruptions, as the Matching process would need to restart. The impact is limited to availability; no data theft or modification is possible.

Compliance Impact

This vulnerability primarily affects service availability and could lead to prolonged downtime if exploited. While it does not directly compromise data confidentiality or integrity, extended outages may violate availability requirements in GDPR, HIPAA, and other regulations that mandate timely access to systems handling personal or health data. Organizations must ensure patches are applied to maintain compliance.

Mitigation Strategies

Update the sqlparser dependency in Temporal Server to the latest version that removes MySQL special comment parsing. Apply the security patches from Temporal releases v1.31.3, v1.30.7, or v1.29.8 which include the fix. Ensure the ListWorkers API is properly secured with namespace read permissions to prevent unauthorized access.

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