{"id":"UBUNTU-CVE-2026-53524","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.","modified":"2026-09-02T19:35:54.290968254Z","published":"2026-08-21T23:16:00Z","upstream":["CVE-2026-53524"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-53524"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-53524"},{"type":"REPORT","url":"https://github.com/weechat/weechat/security/advisories/GHSA-v2v4-45wm-5cr3"},{"type":"REPORT","url":"https://weechat.org/doc/weechat/security/WSA-2026-1/"}],"affected":[{"package":{"name":"weechat","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/weechat?arch=source&distro=esm-apps%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.3-1","1.3-1build1","1.4-1","1.4-1build1","1.4-1build2","1.4-2","1.4-2ubuntu0.1","1.4-2ubuntu0.1+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"weechat","binary_version":"1.4-2ubuntu0.1+esm1"},{"binary_version":"1.4-2ubuntu0.1+esm1","binary_name":"weechat-core"},{"binary_name":"weechat-curses","binary_version":"1.4-2ubuntu0.1+esm1"},{"binary_version":"1.4-2ubuntu0.1+esm1","binary_name":"weechat-plugins"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-53524.json"}},{"package":{"name":"weechat","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/weechat?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.9.1-1","1.9.1-1build1","1.9.1-1ubuntu1","1.9.1-1ubuntu1+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"weechat","binary_version":"1.9.1-1ubuntu1+esm1"},{"binary_version":"1.9.1-1ubuntu1+esm1","binary_name":"weechat-core"},{"binary_name":"weechat-curses","binary_version":"1.9.1-1ubuntu1+esm1"},{"binary_name":"weechat-plugins","binary_version":"1.9.1-1ubuntu1+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-53524.json"}},{"package":{"name":"weechat","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/weechat?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.6-2","2.6-2build1","2.6-2build2","2.6-2ubuntu1","2.6-2ubuntu2","2.8-1","2.8-1ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"weechat","binary_version":"2.8-1ubuntu0.1~esm1"},{"binary_name":"weechat-core","binary_version":"2.8-1ubuntu0.1~esm1"},{"binary_name":"weechat-curses","binary_version":"2.8-1ubuntu0.1~esm1"},{"binary_name":"weechat-guile","binary_version":"2.8-1ubuntu0.1~esm1"},{"binary_name":"weechat-headless","binary_version":"2.8-1ubuntu0.1~esm1"},{"binary_name":"weechat-lua","binary_version":"2.8-1ubuntu0.1~esm1"},{"binary_name":"weechat-perl","binary_version":"2.8-1ubuntu0.1~esm1"},{"binary_name":"weechat-php","binary_version":"2.8-1ubuntu0.1~esm1"},{"binary_name":"weechat-plugins","binary_version":"2.8-1ubuntu0.1~esm1"},{"binary_version":"2.8-1ubuntu0.1~esm1","binary_name":"weechat-python"},{"binary_name":"weechat-ruby","binary_version":"2.8-1ubuntu0.1~esm1"},{"binary_version":"2.8-1ubuntu0.1~esm1","binary_name":"weechat-tcl"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-53524.json"}},{"package":{"name":"weechat","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/weechat?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3-1","3.3-1ubuntu1","3.4-2","3.4-2build1","3.4-2build2","3.4.1-1","3.5-1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.5-1","binary_name":"weechat"},{"binary_name":"weechat-core","binary_version":"3.5-1"},{"binary_name":"weechat-curses","binary_version":"3.5-1"},{"binary_name":"weechat-guile","binary_version":"3.5-1"},{"binary_name":"weechat-headless","binary_version":"3.5-1"},{"binary_name":"weechat-lua","binary_version":"3.5-1"},{"binary_name":"weechat-perl","binary_version":"3.5-1"},{"binary_version":"3.5-1","binary_name":"weechat-php"},{"binary_version":"3.5-1","binary_name":"weechat-plugins"},{"binary_name":"weechat-python","binary_version":"3.5-1"},{"binary_version":"3.5-1","binary_name":"weechat-ruby"},{"binary_name":"weechat-tcl","binary_version":"3.5-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-53524.json"}},{"package":{"name":"weechat","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/weechat?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.5-1","4.1.1-1","4.1.1-1build2","4.1.1-1build3","4.1.1-1build6","4.1.1-1build7"],"ecosystem_specific":{"binaries":[{"binary_name":"weechat","binary_version":"4.1.1-1build7"},{"binary_version":"4.1.1-1build7","binary_name":"weechat-core"},{"binary_version":"4.1.1-1build7","binary_name":"weechat-curses"},{"binary_name":"weechat-guile","binary_version":"4.1.1-1build7"},{"binary_name":"weechat-headless",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