CVE-2026-46373: SQLFluff Recursive Stack Overflow Vulnerability

HIGH
Advisory Identifier: GHSA-wmhf-fqc8-vxhh
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CVSS 7.5
CWE-674
Published
Advisory Summary

CVE-2026-46373 is a HIGH (CVSS 7.5) recursive stack overflow vulnerability (CWE-674: Uncontrolled Recursion) affecting SQLFluff libraries in the PyPI ecosystem. The issue involves recursive stack overflow in parser. Remediation is available by upgrading affected packages to version 4.1.0.

CVE-2026-46373 at a Glance

CVE Identifier CVE-2026-46373
GHSA Identifier GHSA-wmhf-fqc8-vxhh
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-674: Uncontrolled Recursion
Affected Product SQLFluff
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-46373

To remediate this vulnerability, upgrade all affected SQLFluff dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

sqlfluff fixed: 4.1.0 
pip install sqlfluff>=4.1.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show sqlfluff

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-46373, inspect your installed packages using pip:

pip show sqlfluff

Analyze the terminal output to locate any version of SQLFluff in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.1.0), your application is affected.

Note: The pip show sqlfluff command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-674: Uncontrolled Recursion, where the product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack. In SQLFluff, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact In deployments where untrusted users can provide SQL queries to be linted, an untrusted user can submit a malicious query with deliberate excessive nesting to any application using the parser to trigger a Denial of Service through resource exhaustion. ### Patches Versions 4.1.0 and up contain a configurable recursion limit, which is enabled by default, to prevent this manner of exploit. ### Credit Ori Nakar from Imperva Threat Research Team.

CVE-2026-46373 Affected SQLFluff Versions

1 component(s)
Fixed Versions:
4.1.0
Product / Package Ecosystem Affected Versions Fixed Version
sqlfluff
pypi/sqlfluff
PyPI
< 4.1.0
4.1.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/sqlfluff/sqlfluff/security/advisories/GHSA-wmhf-fqc8-vxhh
NVD — CVE-2026-46373 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-46373
SQLFluff Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/sqlfluff/PYSEC-2026-209.yaml
SQLFluff Source Repository REPOSITORY
https://github.com/sqlfluff/sqlfluff

Frequently Asked Questions

What is CVE-2026-46373?
CVE-2026-46373 is a security vulnerability in SQLFluff involving Recursive Stack Overflow in Parser under CWE-674: Uncontrolled Recursion.
Which SQLFluff versions are affected?
Affected versions include releases prior to 4.1.0 across affected packages: sqlfluff.
What version fixes CVE-2026-46373?
Upgrading to 4.1.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is sqlfluff affected?
Yes, sqlfluff is affected in releases prior to 4.1.0. Upgrade your dependency to 4.1.0 or later.
What is the CVSS score of CVE-2026-46373?
CVE-2026-46373 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-46373?
CVE-2026-46373 is classified under CWE-674: Uncontrolled Recursion (The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.).
How can I check PyPI dependencies for CVE-2026-46373?
Run the dependency tree command: 'pip show sqlfluff'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-wmhf-fqc8-vxhh",
  "modified" : "2026-07-06T22:53:18Z",
  "published" : "2026-05-19T20:10:17Z",
  "aliases" : [ "CVE-2026-46373" ],
  "summary" : "SQLFluff: Recursive Stack Overflow in Parser",
  "details" : "### Impact\n\nIn deployments where untrusted users can provide SQL queries to be linted, an untrusted user can submit a malicious query with deliberate excessive nesting to any application using the parser to trigger a Denial of Service through resource exhaustion.\n\n### Patches\n\nVersions 4.1.0 and up contain a configurable recursion limit, which is enabled by default, to prevent this manner of exploit.\n\n### Credit\n\nOri Nakar from Imperva Threat Research Team.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "sqlfluff"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.1.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/sqlfluff/sqlfluff/security/advisories/GHSA-wmhf-fqc8-vxhh"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-46373"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/sqlfluff/PYSEC-2026-209.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/sqlfluff/sqlfluff"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-674" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-19T20:10:17Z",
    "nvd_published_at" : "2026-06-09T23:16:59Z"
  }
}