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TI-2026-79490 Aliases CVE-2026-115508GHSA-q4c3-mqc5-j3m8

Regex backtracking in Crawl4AI /crawl freezes the server

Priority MEDIUM 64CWE-1333Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-1333.

Summary

Crawl4AI from 0.7.0 before 0.9.5 contains an inefficient regular expression complexity flaw (CWE-1333) in its Docker API server. An authenticated API client can supply unbounded regular expressions in /crawl request bodies, and a crafted page can then trigger catastrophic backtracking that freezes the entire server, including /health. The CVSS 4.0 vector shows a network attacker with low privileges and no user interaction, with high availability impact. Public proof-of-concept exploitation is noted, but the flaw is not listed in CISA KEV.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00459 39th percentileScored 2026-11-07
Fix Fixed crawl4ai (unclecode): 0.9.5

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
unclecodecrawl4ai0.7.0 to before 0.9.50.9.5Patch availableCNA
  • crawl4ai Vendorunclecode Affected 0.7.0 to before 0.9.5 Fixed in 0.9.5 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:kidocode:crawl4ai:*:*:*:*:*:*:*:*——unclecode
  • cpe:2.3:a:kidocode:crawl4ai:*:*:*:*:*:*:*:* Versions — — ·unclecode

Remediation

Upgrade unclecode crawl4ai to version 0.9.5, the fixed version. The sources list no vendor advisory identifier for this fix.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA crawl4ai (unclecode) Fixed in 0.9.5

Timeline

  1. 2026-10-22 Threatist record created from CVE-2026-115508
  2. 2026-10-22 Alias added: GHSA-q4c3-mqc5-j3m8
  3. 2026-10-23 Priority changed: MEDIUM → LOW
  4. 2026-10-29 CISA SSVC decision points changed
  5. 2026-10-29 Priority changed: LOW → MEDIUM

References

Patch 1

Advisory 1

Other 2

  • TI-2026-38760 Crawl4AI: AST Sandbox Escape via gi_frame.f_back Chain - Pre-Auth RCE in Docker API CVSS 3.1CRITICAL 10.0
  • TI-2026-40630 Crawl4AI - Authentication Bypass via Hardcoded JWT Signing Key CVSS 4.0CRITICAL 9.3
  • TI-2026-82637 Denial of service in Crawl4AI via unbounded CrawlerRunConfig delay fields CVSS 4.0HIGH 8.7
  • TI-2026-62075 crawl4ai before 0.9.3 Arbitrary File Write via PDFContentScrapingStrategy CVSS 4.0HIGH 8.7
  • TI-2026-82640 Blind SSRF in Crawl4AI Docker server via CacheValidator freshness check CVSS 4.0MEDIUM 6.9
  • TI-2026-82638 Untrusted model loading in Crawl4AI via CosineStrategy model_name CVSS 4.0HIGH 7.7
See all 32 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences