{"id":"CVE-2026-53524","summary":"WeeChat has a Decompression Bomb in Relay WebSocket (DoS)","details":"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.","aliases":["GHSA-v2v4-45wm-5cr3"],"modified":"2026-08-23T18:50:34.899253731Z","published":"2026-08-21T22:18:23.432Z","related":["openSUSE-SU-2026:11481-1","openSUSE-SU-2026:21615-1"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-409"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53524.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53524.json"},{"type":"ADVISORY","url":"https://github.com/weechat/weechat/security/advisories/GHSA-v2v4-45wm-5cr3"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53524"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/weechat/weechat","events":[{"introduced":"b407de4c3be2db851927acd0c09e9980d254e052"},{"fixed":"2148829ebe47d8ac2377ef234162bf6b64c5b466"}],"database_specific":{"source":["AFFECTED_FIELD","DESCRIPTION"],"extracted_events":[{"introduced":"4.3.0"},{"fixed":"4.9.1"},{"fixed":"4.9.0"}]}}],"versions":["v4.9.0","v4.8.0","v4.7.0","v4.6.0","v4.5.0","v4.4.0","v4.3.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53524.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}