{"id":"CVE-2026-53524","state":"PUBLISHED","title":"WeeChat has a Decompression Bomb in Relay WebSocket (DoS)","description":"WeeChat (Wee Enhanced Environment for Chat) is a free chat client. In versions 4.3.0 through 4.9.0, the WeeChat relay module's WebSocket permessage-deflate decompression function relay_websocket_inflate() has no upper bound on output size. An authenticated relay user can send a small compressed WebSocket frame (~100 bytes) that decompresses to gigabytes, exhausting all server memory and crashing the entire WeeChat process. The api protocol enables permessage-deflate and requires authentication before WebSocket upgrade. Version 4.9.1 patches the issue.","publishedAt":"2026-08-21T22:18:23.432Z","updatedAt":"2026-08-24T20:09:16.871Z","severity":{"score":6.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["weechat weechat"],"affected":[{"vendor":"weechat","product":"weechat","versions":[{"version":">= 4.3.0, < 4.9.1","status":"affected"}]}],"references":["https://github.com/weechat/weechat/security/advisories/GHSA-v2v4-45wm-5cr3"],"weaknesses":["CWE-409"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53524.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53524","state":"PUBLISHED","datePublished":"2026-08-21T22:18:23.432Z","dateUpdated":"2026-08-24T20:09:16.871Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-09T17:30:33.456Z"},"containers":{"cna":{"title":"WeeChat has a Decompression Bomb in Relay WebSocket (DoS)","descriptions":[{"lang":"en","value":"WeeChat (Wee Enhanced Environment for Chat) is a free chat client. In versions 4.3.0 through 4.9.0, the WeeChat relay module's WebSocket permessage-deflate decompression function relay_websocket_inflate() has no upper bound on output size. An authenticated relay user can send a small compressed WebSocket frame (~100 bytes) that decompresses to gigabytes, exhausting all server memory and crashing the entire WeeChat process. The api protocol enables permessage-deflate and requires authentication before WebSocket upgrade. Version 4.9.1 patches the issue."}],"affected":[{"vendor":"weechat","product":"weechat","versions":[{"version":">= 4.3.0, < 4.9.1","status":"affected"}]}],"references":[{"url":"https://github.com/weechat/weechat/security/advisories/GHSA-v2v4-45wm-5cr3","name":"https://github.com/weechat/weechat/security/advisories/GHSA-v2v4-45wm-5cr3","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-409","lang":"en","description":"CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-21T22:18:23.432Z"},"source":{"advisory":"GHSA-v2v4-45wm-5cr3","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/weechat/weechat/security/advisories/GHSA-v2v4-45wm-5cr3","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-24T20:09:05.967952Z","id":"CVE-2026-53524","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-24T20:09:16.871Z"}}]}}}