{"id":"CVE-2026-85534","title":"A flaw was found in libsoup","summary":"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_I…","severity":"medium","cvss":5.9,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-617"],"published":"2026-09-04","updated":"2026-09-08","sourceUpdated":"2026-09-08T19:08:15.590","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-85534","references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-85534","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2528440","label":"secalert@redhat.com"},{"url":"https://gitlab.gnome.org/GNOME/libsoup/-/blob/master/libsoup/http2/soup-client-message-io-http2.c","label":"secalert@redhat.com"},{"url":"https://gitlab.gnome.org/GNOME/libsoup/-/work_items/551","label":"secalert@redhat.com"}],"tags":["nvd"],"epss":0.00315,"epssPercentile":0.24702,"ingestedAt":"2026-09-08T20:10:03.164Z","slug":"CVE-2026-85534","body":"## Overview\n\nA 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":33,"depthScoreParts":{"impact":32.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}