Vulnerability · Published Sep 21, 2026 · Assigned by Temporal

CVE-2026-65651temporalio/sqlparser deeply nested unary expressions can cause a fatal stack overflow during AST traversal

High 8.7

In plain English

A high-severity security flaw in Temporal Server from Temporal Technologies, Inc.. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities).

Severity (CVSS 4.0)8.7High
Exploit odds (30 days)0.7%top 47.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

temporalio/sqlparser accepts SQL containing deeply nested unary expressions and can return a correspondingly deep abstract syntax tree without enforcing an applicable nesting limit. The library's String and Walk operations recursively traverse that tree. An application that parses attacker-controlled SQL and later formats or walks the returned tree can encounter a runtime-fatal Go stack overflow that terminates the process; Go panic recovery cannot contain this condition. Temporal Server passes caller-controlled query input through the affected parser in archival, visibility, and worker-query paths. In affected validation paths, the Server recursively formats an invalid expression while constructing an error. In a supported authenticated deployment, a caller with namespace read permission can terminate the receiving Frontend or Matching process. The dynamically confirmed ListWorkers route additionally requires at least one retained worker heartbeat. Repeated requests can sustain a denial of service. The issue affects availability only; no confidentiality or integrity impact was identified.

Affected products (as reported)

VendorProductVersions
Temporal Technologies, Inc. temporalio/sqlparser 0.0.0-20141206041240-1aae9baceee8 – before 0.0.0-20260721183058-0466b6b405ac
Temporal Technologies, Inc. Temporal Server 0.10.0 – through 1.29.71.30.0 – before 1.30.71.31.0 – before 1.31.3

Weakness: CWE-674 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References