{"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-2020-26257 in the wild and no public exploit code.","fix":"Upgrade matrix-synapse to 1.23.1 or later.","what":"CVE-2020-26257 is a medium-severity denial of service vulnerability in Fedoraproject Fedora, published on 9 Dec 2020. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2020-26257 and fix it if it is affected.\n\nWhat it is: CVE-2020-26257 is a medium-severity denial of service vulnerability in Fedoraproject Fedora, published on 9 Dec 2020. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2020-26257 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- matrix-synapse (PyPI): affected all versions; fixed in 1.23.1\n- matrix-synapse (PyPI): affected all versions; fixed in 1.23.1\n- matrix-synapse (PyPI): affected all versions; fixed in 1.23.1\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-2020-26257/ (Markdown: https://insights.sbomify.com/CVE-2020-26257/index.md)","id":"CVE-2020-26257","markdown":"https://insights.sbomify.com/CVE-2020-26257/index.md","name":"CVE-2020-26257","record":{"aliases":["GHSA-hxmp-pqch-c8mm","PYSEC-2020-236","UBUNTU-CVE-2020-26257"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Matrix Synapse homeserver","requires_auth":"low_privilege","summary":"A malicious homeserver can cause denial of service in Matrix Synapse by injecting malformed events via federation APIs, affecting all servers accepting untrusted federation requests.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"fedora","vendor":"fedoraproject"},{"product":"synapse","vendor":"matrix"}],"cvss":{"score":6.5,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"},{"id":"CWE-400","name":"Uncontrolled Resource Consumption"}],"description":"Matrix is an ecosystem for open federated Instant Messaging and VoIP. Synapse is a reference \"homeserver\" implementation of Matrix. A malicious or poorly-implemented homeserver can inject malformed events into a room by specifying a different room id in the path of a `/send_join`, `/send_leave`, `/invite` or `/exchange_third_party_invite` request. This can lead to a denial of service in which future events will not be correctly sent to other servers over federation. This affects any server which accepts federation requests from untrusted servers. The Matrix Synapse reference implementation before version 1.23.1 the implementation is vulnerable to this injection attack. Issue is fixed in version 1.23.1. As a workaround homeserver administrators could limit access to the federation API to trusted servers (for example via `federation_domain_whitelist`).","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 via incorrect parameters to federation APIs","id":"CVE-2020-26257","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":6,"next":{"headline":"Server-Side Forgery Request can be activated unmarshalling with XStream","id":"CVE-2020-26258"},"packages":[{"ecosystem":"PyPI","fixed":["1.23.1"],"introduced":["0"],"last_affected":[],"package":"matrix-synapse","purl":null,"source":"GHSA-hxmp-pqch-c8mm"},{"ecosystem":"PyPI","fixed":["1.23.1"],"introduced":["0"],"last_affected":[],"package":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","source":"GHSA-hxmp-pqch-c8mm"},{"ecosystem":"PyPI","fixed":["1.23.1"],"introduced":["0"],"last_affected":[],"package":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","source":"PYSEC-2020-236"}],"prev":{"headline":"Denial of service in fast-csv","id":"CVE-2020-26256"},"products":["synapse"],"published":"2020-12-09","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":["matrix-org"]},"summary":"A malicious homeserver can cause denial of service in Matrix Synapse by injecting malformed events via federation APIs, affecting all servers accepting untrusted federation requests.","url":"https://insights.sbomify.com/CVE-2020-26257/"}