CVE-2026-71491
highpriority · track · 0EPSS 0.003 · 18 %ileDEEUUSEPSS · scored 2026-10-28
sqlparse is a non-validating SQL parser module for Python. Prior to 0.6.0, group_comments in sqlparse/engine/grouping.py repeatedly rescans comment-only statements before the MAX_GROUPING_TOKENS guard, causing quadratic CPU consumption through sqlparse.parse() and sqlparse.format(sql, strip_comments=True). This issue is fixed in version 0.6.0.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.6–8.7
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (6)
Products and version ranges known to be affected.
- Red Hat Ansible Automation Platform 2.4all versionscert_bundDEcpe:/a:redhat:ansible_automation_platform:2.4
- Red Hat Ansible Automation Platform 2.7all versionscert_bundDEcpe:/a:redhat:ansible_automation_platform:2.7
advisories (3)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-3555Red Hat Ansible Automation Platform (automation-controller): Mehrere SchwachstellenDeutsch2026-09-23csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Red Hat Ansible Automation Platform ausnutzen, um seine Privilegien zu erhöhen, beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren oder offenzulegen und einen Denial-of-Service-Zustand herbeizuführen.
- GHSA-f2ff-p2ww-7p4psqlparse: Quadratic O(n²) DoS in group_comments2026-08-17ghsa · osvUS
### Summary A comment-only statement (`-- c\n`*n) may cause a Denial of Service (DoS). ### Details Location: [sqlparse/engine/grouping.py:331-341](https://github.com/andialbrecht/sqlparse/blob/f80af6a4007f11ada847218df8c29dc859238290/sqlparse/engine/grouping.py#L332) (`group_comments`), invoked first in `group()` at `grouping.py:439`. Reachable via `sqlparse.parse()` and `sqlparse.format(sql, strip_comments=True)`. A statement made of many single-line comments (`'-- c\n'` repeated) lexes in O(n) but `group_comments` is O(n²): ```python def group_comments(tlist): tidx, token = tlist.token_next_by(t=T.Comment) while token: eidx, end = tlist.token_not_matching( lambda tk: imt(tk, t=T.Comment) or tk.is_newline, idx=tidx) ... tidx, token = tlist.token_next_by(t=T.Comment, idx=tidx) ``` The `while` loop runs n times and each `token_next_by` / `token_not_matching` rescans the O(n) remaining tokens. When all tokens are comments/newlines nothing ever groups, yet the full scan is repeated per token. Two following factors increase the severity: 1. `group_comments` runs first in `group()` (`grouping.py:439`), before the `_group_matching` token-count guard (`grouping.py:34-39`). So the entire quadratic cost is paid even on oversized input. `MAX_GROUPING_TOKENS` does not provide protection on this vector. 2. It sits on the primary sanitizer path: `format(sql, strip_comments=True)`, used by query loggers, SQL firewalls, ORMs, and migration tools. ### PoC Tested using Python 3.14: ```python import time, sqlparse for n in (1000, 2000, 4000): s = "-- c\n" * n t = time.perf_counter() sqlparse.format(s, strip_comments=True) print(f"n={n:5d} format(strip_comments)={1000*(time.perf_counter()-t):7.1f} ms") ``` Output: ``` n= 1000 format(strip_comments)= 106.0 ms n= 2000 format(strip_comments)= 403.3 ms n= 4000 format(strip_comments)= 1602.8 ms ``` Time increase of ~4× per 2× input (quadratic). `parse()` shows the identical curve. Instrumented scan counts are exactly 1.0M / 4.0M / 16.0M tokens for n=1000/2000/4000. A ~250 KB comment-only payload forces minutes of CPU regardless of the 10000 token cap. ### Impact Denial of Service
- PYSEC-2026-3697sqlparse: Quadratic O(n²) DoS in group_comments2026-08-19vendor · osvUS
### Summary A comment-only statement (`-- c\n`*n) may cause a Denial of Service (DoS). ### Details Location: [sqlparse/engine/grouping.py:331-341](https://github.com/andialbrecht/sqlparse/blob/f80af6a4007f11ada847218df8c29dc859238290/sqlparse/engine/grouping.py#L332) (`group_comments`), invoked first in `group()` at `grouping.py:439`. Reachable via `sqlparse.parse()` and `sqlparse.format(sql, strip_comments=True)`. A statement made of many single-line comments (`'-- c\n'` repeated) lexes in O(n) but `group_comments` is O(n²): ```python def group_comments(tlist): tidx, token = tlist.token_next_by(t=T.Comment) while token: eidx, end = tlist.token_not_matching( lambda tk: imt(tk, t=T.Comment) or tk.is_newline, idx=tidx) ... tidx, token = tlist.token_next_by(t=T.Comment, idx=tidx) ``` The `while` loop runs n times and each `token_next_by` / `token_not_matching` rescans the O(n) remaining tokens. When all tokens are comments/newlines nothing ever groups, yet the full scan is repeated per token. Two following factors increase the severity: 1. `group_comments` runs first in `group()` (`grouping.py:439`), before the `_group_matching` token-count guard (`grouping.py:34-39`). So the entire quadratic cost is paid even on oversized input. `MAX_GROUPING_TOKENS` does not provide protection on this vector. 2. It sits on the primary sanitizer path: `format(sql, strip_comments=True)`, used by query loggers, SQL firewalls, ORMs, and migration tools. ### PoC Tested using Python 3.14: ```python import time, sqlparse for n in (1000, 2000, 4000): s = "-- c\n" * n t = time.perf_counter() sqlparse.format(s, strip_comments=True) print(f"n={n:5d} format(strip_comments)={1000*(time.perf_counter()-t):7.1f} ms") ``` Output: ``` n= 1000 format(strip_comments)= 106.0 ms n= 2000 format(strip_comments)= 403.3 ms n= 4000 format(strip_comments)= 1602.8 ms ``` Time increase of ~4× per 2× input (quadratic). `parse()` shows the identical curve. Instrumented scan counts are exactly 1.0M / 4.0M / 16.0M tokens for n=1000/2000/4000. A ~250 KB comment-only payload forces minutes of CPU regardless of the 10000 token cap. ### Impact Denial of Service
also known as (4)
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sources
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references (4)
External citations — patches, advisories, analysis.
- https://github.com/andialbrecht/sqlparse/commit/ef2012a5eeb491e604dea2b00d516904a3830c87enisa_euvd
- https://github.com/andialbrecht/sqlparse/security/advisories/GHSA-f2ff-p2ww-7p4penisa_euvd
- https://github.com/andialbrecht/sqlparse/commit/ef2012a5eeb491e604dea2b00d516904a3830c87nvd
- https://github.com/andialbrecht/sqlparse/security/advisories/GHSA-f2ff-p2ww-7p4pnvd
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