CVE-2026-84305 sqlparse: Reindentation of tuple lists causes near-cap quadratic CPU consumption
An attacker can cause excessive CPU consumption and service delays by submitting crafted SQL inputs to the sqlparse library's reindentation feature.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-84305?
CVE-2026-84305 is a medium-severity denial of service vulnerability in andialbrecht sqlparse, published on 1 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
sqlparse is a non-validating SQL parser module for Python. Prior to 0.6.0, sqlparse.format(sql, reindent=True) and sqlformat --reindent route attacker-controlled parenthesized tuple lists through ReindentFilter._get_offset() in sqlparse/filters/reindent.py, where _flatten_up_to_token() repeatedly rebuilds and joins the statement prefix. Thousands of offset calculations walk an expanding token tree, producing quadratic CPU consumption for inputs that remain below MAX_GROUPING_TOKENS and causing request delays, reduced throughput, or worker starvation. This issue is fixed in version 0.6.0.
Weakness: CWE-407
Which versions are affected by CVE-2026-84305?
3 open source packages ship an affected version, including sqlparse.
| Package | Affected | Fixed in |
|---|---|---|
sqlparse PyPI | All versions | 0.6.0 |
sqlparse PyPI | All versions | 0.6.0 |
sqlparse PyPI | All versions | 0.6.0 |
Linux distribution packages (8)
python-sqlparse SUSE:Linux Enterprise Module for Package Hub 15 SP7 | All versions | 0.2.4-150100.6.14.1 |
python-sqlparse SUSE:Linux Enterprise Module for Public Cloud 15 SP4 | All versions | 0.4.4-150400.6.19.1 |
python-sqlparse SUSE:Linux Enterprise Module for Public Cloud 15 SP5 | All versions | 0.4.4-150400.6.19.1 |
python-sqlparse SUSE:Linux Enterprise Module for Public Cloud 15 SP6 | All versions | 0.4.4-150600.3.12.1 |
python-sqlparse SUSE:Linux Enterprise Module for Python 3 15 SP7 | All versions | 0.4.4-150600.3.12.1 |
python-sqlparse SUSE:Linux Enterprise Server 16.0 | All versions | 0.5.3-160000.5.1 |
python-sqlparse SUSE:Linux Enterprise Server for SAP applications 16.0 | All versions | 0.5.3-160000.5.1 |
python-sqlparse openSUSE:Leap 16.0 | All versions | 0.5.3-160000.5.1 |
How do I fix CVE-2026-84305?
Upgrade sqlparse to 0.6.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-84305 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-84305 exists.
Sources
Also known as CLEANSTART-2026-JF73384, CLEANSTART-2026-UP48732, CLEANSTART-2026-WG08246, DEBIAN-CVE-2026-84305, ECHO-8e2d-935c-d158, GHSA-cfqr-cjx5-5jcm and 12 more.