{"affected":[{"defaultStatus":"affected","ecosystem":"https://access.redhat.com/downloads/content/package-browser/","packageName":"libsoup3","product":"Red Hat Enterprise Linux 10","source":"CNA: redhat","vendor":"Red Hat","versions":[]},{"defaultStatus":"unaffected","ecosystem":"https://access.redhat.com/downloads/content/package-browser/","packageName":"libsoup","product":"Red Hat Enterprise Linux 6","source":"CNA: redhat","vendor":"Red Hat","versions":[]},{"defaultStatus":"unaffected","ecosystem":"https://access.redhat.com/downloads/content/package-browser/","packageName":"libsoup","product":"Red Hat Enterprise Linux 7","source":"CNA: redhat","vendor":"Red Hat","versions":[]},{"defaultStatus":"unaffected","ecosystem":"https://access.redhat.com/downloads/content/package-browser/","packageName":"libsoup","product":"Red Hat Enterprise Linux 8","source":"CNA: redhat","vendor":"Red Hat","versions":[]},{"defaultStatus":"unaffected","ecosystem":"https://access.redhat.com/downloads/content/package-browser/","packageName":"libsoup","product":"Red Hat Enterprise Linux 9","source":"CNA: redhat","vendor":"Red Hat","versions":[]}],"cveId":"CVE-2026-85534","cwes":["CWE-617"],"description":"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.","epss":{"date":"2026-11-05","percentile":0.24596,"score":0.00315},"exploits":[],"kev":null,"metrics":[{"score":5.9,"severity":"medium","source":"CNA: redhat","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}],"modifiedAt":1793927298145,"publishedAt":1788517162562,"references":[{"source":"CNA: redhat","tags":["vdb-entry","x_refsource_REDHAT"],"url":"https://access.redhat.com/security/cve/CVE-2026-85534"},{"source":"CNA: redhat","tags":["issue-tracking","x_refsource_REDHAT"],"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2528440"},{"source":"CNA: redhat","tags":[],"url":"https://gitlab.gnome.org/GNOME/libsoup/-/blob/master/libsoup/http2/soup-client-message-io-http2.c"},{"source":"CNA: redhat","tags":[],"url":"https://gitlab.gnome.org/GNOME/libsoup/-/work_items/551"}],"remediation":[{"kind":"workaround","source":"CNA: redhat","text":"Do not HTTP/2-upload from non-pollable streams (e.g. GFileInputStream) to untrusted servers. soup_message_set_request_body_from_bytes() is the pollable path. Assertions abort instead of returning an oversized length; that is not a fix."}],"revision":"e75fef20bcb289e6c1c2ec5c81269cb3f04466ce7ae2dcbc9a461aecb391cf0e","sources":[{"modifiedAt":1793927298145,"name":"CNA: redhat","retrievedAt":1793931009789,"url":"https://www.cve.org/CVERecord?id=CVE-2026-85534"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1793931024019,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-85534"}],"ssvc":{"assessedAt":1788538023334,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"Libsoup: libsoup: http/2 client crash in on_data_source_read_callback when settings initial_window_size shrinks during deferred body read","updatedAt":1793931024019}