{"action":"Upgrade matrix-synapse to 1.152.1 or later.","affected":[{"fixed":"1.152.1","introduced":"0"}],"component":"matrix-synapse","cve_ids":["CVE-2026-45078"],"ecosystem":"PyPI","epss":0.00128,"exploited":false,"fixed_versions":["1.152.1"],"ghsa_id":"GHSA-8q93-326v-3m7g","id":"tcs_01M5KGWD7VQMTET288MD5H0498","modified_at":"2026-06-03T12:45:18.070288002Z","published_at":"2026-05-28T17:16:31.750Z","references":["https://osv.dev/vulnerability/PYSEC-2026-191","https://github.com/element-hq/synapse/security/advisories/GHSA-8q93-326v-3m7g"],"severity":{"label":"medium","score":5.5},"sources":[{"source":"osv","source_id":"PYSEC-2026-191","url":"https://osv.dev/vulnerability/PYSEC-2026-191"}],"summary":"Synapse is an open source Matrix homeserver implementation. Prior to 1.152.1, local authenticated users can cause Synapse to starve other requests of CPU and lead to other requests failing, causing ot"}