VDB
CVE-2026-55520
CVE-2026-55520
PUBLISHED
CVSS 7.1 HIGH
Reported by GitHub_M · Published August 28, 2026
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.
Risk Scores
CVSS 4.0
7.1
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| scrapy | protego | < 0.6.2 |
| PyPI | Protego | 0 |
| scrapy | protego | < 0.6.2, < 0.6.2, < 0.6.2 |
Timeline
- Jun 26, 2026 CVE Published
- Aug 29, 2026 EPSS Score
- Aug 30, 2026 EPSS Score
- Sep 3, 2026 EPSS Score
- Sep 5, 2026 Security Advisory
- Sep 6, 2026 EPSS Score
- Sep 9, 2026 EPSS Score
- Sep 9, 2026 CVE Updated
- Sep 12, 2026 EPSS Score
- Sep 16, 2026 EPSS Score
- Sep 18, 2026 EPSS Score
- Sep 24, 2026 EPSS Score
References
- https://github.com/scrapy/protego/security/advisories/GHSA-wjmf-p669-5m5p x_refsource_CONFIRM
- https://github.com/scrapy/protego/commit/785940181659bf440ba82f1da148fade5087e858 x_refsource_MISC
- https://github.com/scrapy/protego/releases/tag/0.6.2 x_refsource_MISC
- https://nvd.nist.gov/vuln/detail/CVE-2026-55520 advisory
- https://github.com/advisories/GHSA-wjmf-p669-5m5p advisory