CWE-1333Base

Inefficient Regular Expression Complexity

Draft in the CWE catalog · 414 CVEs mapped

414
CVEs mapped
6.5
Median CVSS
What it is

The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.

Recent examples
6.5cvss
CVE-2026-115508

CVE-2026-115508 - MEDIUM Severity Vulnerability

Crawl4AI 0.7.0 before 0.9.5 contains an inefficient regular expression complexity vulnerability in the Docker API server that allows authenticated API clients to supply unbounded regular expressions in /crawl request bodies. Attackers can submit catastrophic-backtracking patterns via RegexExtractionStrategy.custom, RegexChunking.patterns or JsonCss, JsonXPath and JsonLxml schema regex fields against a crafted page to freeze the entire server, including /health.

MEDIUMno explanation yet
—
epss
7.5cvss
CVE-2026-115349

CVE-2026-115349 - HIGH Severity Vulnerability

Mistune from 3.0.0 before 3.3.0 contains an algorithmic complexity denial of service vulnerability in the parse_link_text function in src/mistune/helpers.py. Attackers can submit markdown with deeply nested square brackets triggering quadratic parsing time, exhausting server CPU with small crafted requests.

HIGHno explanation yet
—
epss
5.3cvss
CVE-2026-114603

CVE-2026-114603 - MEDIUM Severity Vulnerability

OpenTelemetry Python provides the Python API and SDK for OpenTelemetry. Prior to 1.45.1, the opentelemetry-api function TraceState.from_header in opentelemetry/trace/span.py, reached through TraceContextTextMapPropagator.extract, parses inbound W3C tracestate headers with an unbounded optional-whitespace regular expression. A malformed header containing a long run of spaces or tabs without a following comma causes quadratic backtracking before the member-count limit is applied. Services using the default W3C Trace Context propagator can therefore spend excessive CPU time on one unauthenticated request when the HTTP server, parser, gateway, or custom carrier accepts a sufficiently large header. The processing can occupy a synchronous worker or delay unrelated requests on the same asynchronous event loop. The impact is limited to availability and does not expose or modify telemetry data or allow code execution. This issue is fixed in version 1.45.1.

MEDIUMno explanation yet
—
epss
The record
Technical detail
CWE ID
CWE-1333
Abstraction
Base
Structure
Simple
Status
Draft
References (7)