{"answers":{"affected":"3 open source packages ship an affected version, including matrix-synapse. It affects 2 products.","exploited":"There is no known exploitation of CVE-2020-26890 in the wild and no public exploit code.","fix":"Upgrade matrix-synapse to 1.20.0 or later.","what":"CVE-2020-26890 is a high-severity denial of service vulnerability in Fedoraproject Fedora, published on 24 Nov 2020. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2020-26890 and fix it if it is affected.\n\nWhat it is: CVE-2020-26890 is a high-severity denial of service vulnerability in Fedoraproject Fedora, published on 24 Nov 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2020-26890 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- matrix-synapse (PyPI): affected all versions; fixed in 1.20.0\n- matrix-synapse (PyPI): affected all versions; fixed in 1.20.0\n- matrix-synapse (PyPI): affected all versions; fixed in 1.20.0\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-2020-26890/ (Markdown: https://insights.sbomify.com/CVE-2020-26890/index.md)","id":"CVE-2020-26890","markdown":"https://insights.sbomify.com/CVE-2020-26890/index.md","name":"CVE-2020-26890","record":{"aliases":["GHSA-4mp3-385r-v63f","PYSEC-2020-237","UBUNTU-CVE-2020-26890"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Matrix Synapse server","requires_auth":"none","summary":"Remote attackers can cause persistent denial of service in Matrix Synapse by sending malformed JSON values in room member events.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mitre","cpe":[{"product":"fedora","vendor":"fedoraproject"},{"product":"synapse","vendor":"matrix"}],"cvss":{"score":7.5,"severity":"high","source":"nvd","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-20","name":"Improper Input Validation"}],"description":"Matrix Synapse before 1.20.0 erroneously permits non-standard NaN, Infinity, and -Infinity JSON values in fields of m.room.member events, allowing remote attackers to execute a denial of service attack against the federation and common Matrix clients. If such a malformed event is accepted into the room's state, the impact is long-lasting and is not fixed by an upgrade to a newer version, requiring the event to be manually redacted instead. Since events are replicated to servers of other room members, the impact is not constrained to the server of the event sender.","ecosystems":["PyPI"],"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":"Denial of service attack due to invalid JSON","id":"CVE-2020-26890","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":"fedoraproject:fedora","products":["fedoraproject:fedora"],"type":"denial_of_service","year":"2020"},"n_packages":3,"n_references":3,"next":{"headline":"Cross-site scripting (XSS) vulnerability in the fallback authentication endpoint","id":"CVE-2020-26891"},"packages":[{"ecosystem":"PyPI","fixed":["1.20.0"],"introduced":["0"],"last_affected":[],"package":"matrix-synapse","purl":null,"source":"GHSA-4mp3-385r-v63f"},{"ecosystem":"PyPI","fixed":["1.20.0"],"introduced":["0"],"last_affected":[],"package":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","source":"GHSA-4mp3-385r-v63f"},{"ecosystem":"PyPI","fixed":["1.20.0"],"introduced":["0"],"last_affected":[],"package":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","source":"PYSEC-2020-237"}],"prev":{"headline":"Security feature bypass in n/a","id":"CVE-2020-26887"},"products":["n/a"],"published":"2020-11-24","related":[{"cvss_score":9.8,"headline":"PHP-CGI OS Command Injection","id":"CVE-2024-4577","kev_date_added":"2024-06-12","published":"2024-06-09"},{"cvss_score":9.8,"headline":"Grafana Authentication Bypass","id":"CVE-2021-39226","kev_date_added":"2022-08-25","published":"2021-10-05"},{"cvss_score":9.8,"headline":"VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow","id":"CVE-2019-5544","kev_date_added":"2021-11-03","published":"2019-12-06"},{"cvss_score":9.6,"headline":"Google Chromium V8 Type Confusion","id":"CVE-2024-4947","kev_date_added":"2024-05-20","published":"2024-05-15"},{"cvss_score":9.6,"headline":"Google Chromium Visuals Use-After-Free","id":"CVE-2024-4671","kev_date_added":"2024-05-13","published":"2024-05-09"},{"cvss_score":9.6,"headline":"Google Chromium Mojo Insufficient Data Validation","id":"CVE-2022-3075","kev_date_added":"2022-09-08","published":"2022-09-26"},{"cvss_score":9.6,"headline":"Google Chromium Indexed DB API Use-After-Free","id":"CVE-2021-30633","kev_date_added":"2021-11-03","published":"2021-10-08"}],"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":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2024-08-04","vendors":["n/a"]},"summary":"Remote attackers can cause persistent denial of service in Matrix Synapse by sending malformed JSON values in room member events.","url":"https://insights.sbomify.com/CVE-2020-26890/"}