CVE-2026-85534
Libsoup: libsoup: http/2 client crash in on_data_source_read_callback when settings initial_window_size shrinks during deferred body read
MEDIUM 5.9
At a glance
- Source
- NVD
- EPSS
- EPSS 0.32 % · percentile 24 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- redhat
- NVD status
- Awaiting Analysis
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.
Weaknesses (CWE)
- CWE-617 — Reachable Assertion
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H | redhat |
| CVSS 3.1 | MEDIUM 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · secalert@redhat.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-70997
- GCVE · GCVE-0-2026-85534
Affected products
| Product | Versions |
|---|---|
| Red Hat · Red Hat Enterprise Linux 10 | |
| Red Hat · Red Hat Enterprise Linux 6 | |
| Red Hat · Red Hat Enterprise Linux 7 | |
| Red Hat · Red Hat Enterprise Linux 8 | |
| Red Hat · Red Hat Enterprise Linux 9 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |