Hi,

The following vulnerability was published for libsoup3.

CVE-2026-85534[0]:
| 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.


If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2026-85534
https://www.cve.org/CVERecord?id=CVE-2026-85534
[1] https://gitlab.gnome.org/GNOME/libsoup/-/work_items/551
[2] https://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/561

Please adjust the affected versions in the BTS as needed.

Regards,
Salvatore