{"id":"UBUNTU-CVE-2026-85534","details":"A flaw was found in libsoup. When a client sends an HTTP/2 request body from a non-pollable input stream, the library can buffer more data than the current flow-control window later allows. A malicious HTTP/2 server can shrink SETTINGS_INITIAL_WINDOW_SIZE while that buffered read is still in progress. The client then copies the full buffer into a smaller DATA callback without a runtime bounds check, which can abort the process or fail the HTTP/2 session.","modified":"2026-09-18T01:00:12.884174037Z","published":"2026-09-04T11:17:00Z","upstream":["CVE-2026-85534"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-85534"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-85534"},{"type":"REPORT","url":"https://gitlab.gnome.org/GNOME/libsoup/-/work_items/551"},{"type":"REPORT","url":"https://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/561"}],"affected":[{"package":{"name":"libsoup2.4","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/libsoup2.4?arch=source&distro=esm-infra-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.50.0-2debian1","2.52.1-1","2.52.2-1","2.52.2-1ubuntu0.1","2.52.2-1ubuntu0.2","2.52.2-1ubuntu0.3","2.52.2-1ubuntu0.3+esm1","2.52.2-1ubuntu0.3+esm2","2.52.2-1ubuntu0.3+esm3","2.52.2-1ubuntu0.3+esm4","2.52.2-1ubuntu0.3+esm5","2.52.2-1ubuntu0.3+esm6","2.52.2-1ubuntu0.3+esm7"],"ecosystem_specific":{"binaries":[{"binary_name":"gir1.2-soup-2.4","binary_version":"2.52.2-1ubuntu0.3+esm7"},{"binary_name":"libsoup-gnome2.4-1","binary_version":"2.52.2-1ubuntu0.3+esm7"},{"binary_version":"2.52.2-1ubuntu0.3+esm7","binary_name":"libsoup2.4-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-85534.json"}},{"package":{"name":"libsoup2.4","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/libsoup2.4?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.60.1-1","2.60.2-1","2.60.2-2","2.60.3-1","2.61.90-1","2.62.0-1","2.62.1-1","2.62.1-1ubuntu0.1","2.62.1-1ubuntu0.3","2.62.1-1ubuntu0.4","2.62.1-1ubuntu0.4+esm1","2.62.1-1ubuntu0.4+esm2","2.62.1-1ubuntu0.4+esm3","2.62.1-1ubuntu0.4+esm4","2.62.1-1ubuntu0.4+esm5","2.62.1-1ubuntu0.4+esm6","2.62.1-1ubuntu0.4+esm7","2.62.1-1ubuntu0.4+esm8"],"ecosystem_specific":{"binaries":[{"binary_version":"2.62.1-1ubuntu0.4+esm8","binary_name":"gir1.2-soup-2.4"},{"binary_name":"libsoup-gnome2.4-1","binary_version":"2.62.1-1ubuntu0.4+esm8"},{"binary_name":"libsoup2.4-1","binary_version":"2.62.1-1ubuntu0.4+esm8"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-85534.json"}},{"package":{"name":"libsoup2.4","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/libsoup2.4?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.68.2-0ubuntu1","2.68.2-1","2.68.2-2","2.68.2-2build2","2.69.90-1","2.70.0-1","2.70.0-1ubuntu0.1","2.70.0-1ubuntu0.2","2.70.0-1ubuntu0.3","2.70.0-1ubuntu0.4","2.70.0-1ubuntu0.5","2.70.0-1ubuntu0.5+esm1","2.70.0-1ubuntu0.5+esm2","2.70.0-1ubuntu0.5+esm3"],"ecosystem_specific":{"binaries":[{"binary_name":"gir1.2-soup-2.4","binary_version":"2.70.0-1ubuntu0.5+esm3"},{"binary_name":"libsoup-gnome2.4-1","binary_version":"2.70.0-1ubuntu0.5+esm3"},{"binary_name":"libsoup2.4-1","binary_version":"2.70.0-1ubuntu0.5+esm3"},{"binary_name":"libsoup2.4-tests","binary_version":"2.70.0-1ubuntu0.5+esm3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-85534.json"}},{"package":{"name":"libsoup2.4","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libsoup2.4?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.72.0-3ubuntu3","2.74.1-1","2.74.2-2","2.74.2-3","2.74.2-3ubuntu0.1","2.74.2-3ubuntu0.2","2.74.2-3ubuntu0.3","2.74.2-3ubuntu0.4","2.74.2-3ubuntu0.5","2.74.2-3ubuntu0.6","2.74.2-3ubuntu0.7","2.74.2-3ubuntu0.8"],"ecosystem_specific":{"binaries":[{"binary_name":"gir1.2-soup-2.4","binary_version":"2.74.2-3ubuntu0.8"},{"binary_name":"libsoup-gnome2.4-1","binary_version":"2.74.2-3ubuntu0.8"},{"binary_name":"libsoup2.4-1","binary_version":"2.74.2-3ubuntu0.8"},{"binary_name":"libsoup2.4-common","binary_version":"2.74.2-3ubuntu0.8"},{"binary_version":"2.74.2-3ubuntu0.8","binary_name":"libsoup2.4-tests"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-85534.json"}},{"package":{"name":"libsoup3","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/libsoup3?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.4-2","3.0.4-3","3.0.5-1","3.0.7-0ubuntu1","3.0.7-0ubuntu1+esm1","3.0.7-0ubuntu1+esm2","3.0.7-0ubuntu1+esm3","3.0.7-0ubuntu1+esm4","3.0.7-0ubuntu1+esm5","3.0.7-0ubuntu1+esm6","3.0.7-0ubuntu1+esm7","3.0.7-0ubuntu1+esm8"],"ecosystem_specific":{"binaries":[{"binary_name":"gir1.2-soup-3.0","binary_version":"3.0.7-0ubuntu1+esm8"},{"binary_name":"libsoup-3.0-0","binary_version":"3.0.7-0ubuntu1+esm8"},{"binary_name":"libsoup-3.0-common","binary_version":"3.0.7-0ubuntu1+esm8"},{"binary_name":"libsoup-3.0-tests","binary_version":"3.0.7-0ubuntu1+esm8"}]},"database_specific":{"source":"https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