CVE-2026-55520

Protego is a pure-Python robots.txt parser with support for modern conventions. Prior to 0.6.2, protego._urlpattern._URLPattern._prepare_pattern_for_regex translates every asterisk in an Allow or Disallow directive into a lazy regular-expression wildcard, so a directive containing many asterisks creates exponential backtracking. After protego.Protego.parse processes a crafted robots.txt file, protego.Protego.can_fetch can spend an attacker-controlled period matching a near-miss URL and deny service to the crawler. The vulnerable path is src/protego/_urlpattern.py in the _URLPattern match logic. This issue is fixed in version 0.6.2.

CVSS

No CVSS.

References

Link	Resource
https://github.com/scrapy/protego/commit/785940181659bf440ba82f1da148fade5087e858
https://github.com/scrapy/protego/releases/tag/0.6.2
https://github.com/scrapy/protego/security/advisories/GHSA-wjmf-p669-5m5p

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-28 20:18

Updated : 2026-09-09 21:09

NVD link : CVE-2026-55520

Mitre link : CVE-2026-55520

CVE.ORG link : CVE-2026-55520

JSON object : View

Products Affected

No product.

CWE

CWE-400

Uncontrolled Resource Consumption

CWE-1333

Inefficient Regular Expression Complexity

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