{"answers":{"affected":"3 open source packages ship an affected version, including protego and Protego.","exploited":"There is no known exploitation of CVE-2026-55520 in the wild and no public exploit code.","fix":"Upgrade protego to 0.6.2 or later.","what":"CVE-2026-55520 is a high-severity denial of service vulnerability in scrapy protego, published on 28 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-55520 and fix it if it is affected.\n\nWhat it is: CVE-2026-55520 is a high-severity denial of service vulnerability in scrapy protego, published on 28 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-55520 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- protego (PyPI): affected all versions; fixed in 0.6.2\n- protego (PyPI): affected all versions; fixed in 0.6.2\n- Protego (PyPI): affected all versions; fixed in 0.6.2\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-55520/ (Markdown: https://insights.sbomify.com/CVE-2026-55520/index.md)","id":"CVE-2026-55520","markdown":"https://insights.sbomify.com/CVE-2026-55520/index.md","name":"CVE-2026-55520","record":{"aliases":["DEBIAN-CVE-2026-55520","GHSA-wjmf-p669-5m5p","PYSEC-2026-3906","UBUNTU-CVE-2026-55520","openSUSE-SU-2026:11202-1"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Python robots.txt parser","requires_auth":"none","summary":"Attackers can cause denial of service in Protego by crafting robots.txt files that trigger exponential backtracking during URL matching.","user_interaction":"required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":7.1,"severity":"high","source":"cna","vector":"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","version":"4.0"},"cwes":[{"id":"CWE-400","name":"Uncontrolled Resource Consumption"},{"id":"CWE-1333","name":"Inefficient Regular Expression Complexity"}],"description":"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.","ecosystems":["PyPI","openSUSE:Tumbleweed"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Protego: Exponential backtracking ReDoS in robots.txt URL wildcard matching","id":"CVE-2026-55520","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":4,"n_references":3,"next":{"headline":"Yamcs : Multiple Missing Function Level Access Control vulnerabilities in Yamcs Core API","id":"CVE-2026-55521"},"packages":[{"ecosystem":"PyPI","fixed":["0.6.2"],"introduced":["0"],"last_affected":[],"package":"Protego","purl":null,"source":"GHSA-wjmf-p669-5m5p"},{"ecosystem":"PyPI","fixed":["0.6.2"],"introduced":["0"],"last_affected":[],"package":"protego","purl":"pkg:pypi/protego","source":"GHSA-wjmf-p669-5m5p"},{"ecosystem":"PyPI","fixed":["0.6.2"],"introduced":["0"],"last_affected":[],"package":"protego","purl":"pkg:pypi/protego","source":"PYSEC-2026-3906"},{"ecosystem":"openSUSE:Tumbleweed","fixed":["0.6.2-1.1"],"introduced":["0"],"last_affected":[],"package":"python-Protego","purl":"pkg:rpm/opensuse/python-Protego\u0026distro=openSUSE%20Tumbleweed","source":"openSUSE-SU-2026:11202-1"}],"prev":{"headline":"Snipe-IT: Improper Authorization in File Deletion (IDOR)","id":"CVE-2026-55519"},"products":["protego"],"published":"2026-08-28","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CC BY 4.0","name":"PyPA Advisory Database","prefix":"PYSEC"},{"class":"attribution","licence":"CC BY 4.0","name":"SUSE","prefix":"openSUSE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-08-31","vendors":["scrapy"]},"summary":"Attackers can cause denial of service in Protego by crafting robots.txt files that trigger exponential backtracking during URL matching.","url":"https://insights.sbomify.com/CVE-2026-55520/"}