{"answers":{"affected":"3 open source packages ship an affected version, including matrix-synapse. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-45076 in the wild and no public exploit code.","fix":"Upgrade matrix-synapse to 1.152.1 or later.","what":"CVE-2026-45076 is a medium-severity denial of service vulnerability in element-hq synapse, published on 28 May 2026. An attacker needs administrator access to exploit it, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-45076 and fix it if it is affected.\n\nWhat it is: CVE-2026-45076 is a medium-severity denial of service vulnerability in element-hq synapse, published on 28 May 2026. An attacker needs administrator access to exploit it, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-45076 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- matrix-synapse (PyPI): affected all versions; fixed in 1.152.1\n- matrix-synapse (PyPI): affected all versions; fixed in 1.152.1\n- matrix-synapse (PyPI): affected all versions; fixed in 1.152.1\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-2026-45076/ (Markdown: https://insights.sbomify.com/CVE-2026-45076/index.md)","id":"CVE-2026-45076","markdown":"https://insights.sbomify.com/CVE-2026-45076/index.md","name":"CVE-2026-45076","record":{"aliases":["GHSA-6qf2-7x63-mm6v","PYSEC-2026-194","UBUNTU-CVE-2026-45076"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Matrix homeserver","requires_auth":"high_privilege","summary":"Malicious homeservers can prevent Synapse from providing full history to clients, causing a denial of service for room history display.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"synapse","vendor":"element"}],"cvss":{"score":5.1,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-20","name":"Improper Input Validation"}],"description":"Synapse is an open source Matrix homeserver implementation. Prior to 1.152.1, in federated rooms, malicious homeservers can craft room events in such a way that prevents Synapse from providing full history to paginating clients. Clients could therefore fail to display room history. This vulnerability is fixed in 1.152.1.","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":"Synapse pagination denial of service","id":"CVE-2026-45076","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":3,"n_references":1,"next":{"headline":"Symfony: Unauthenticated PHP Object Deserialization in MonologBridge server:log Listener","id":"CVE-2026-45077"},"packages":[{"ecosystem":"PyPI","fixed":["1.152.1"],"introduced":["0"],"last_affected":[],"package":"matrix-synapse","purl":null,"source":"GHSA-6qf2-7x63-mm6v"},{"ecosystem":"PyPI","fixed":["1.152.1"],"introduced":["0"],"last_affected":[],"package":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","source":"GHSA-6qf2-7x63-mm6v"},{"ecosystem":"PyPI","fixed":["1.152.1"],"introduced":["0"],"last_affected":[],"package":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","source":"PYSEC-2026-194"}],"prev":{"headline":"Symfony: HEAD Request Bypasses methods: ['GET'] Filter in #[IsGranted] / #[IsSignatureValid] / #[IsCsrfTokenValid]","id":"CVE-2026-45075"},"products":["synapse"],"published":"2026-05-28","related":[{"cvss_score":6.8,"headline":"Synapse CPU starvation (Denial of Service)","id":"CVE-2026-45078","kev_date_added":null,"published":"2026-05-28"}],"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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-06-02","vendors":["element-hq"]},"summary":"Malicious homeservers can prevent Synapse from providing full history to clients, causing a denial of service for room history display.","url":"https://insights.sbomify.com/CVE-2026-45076/"}