Reachable Assertion Affecting libsoup3-devel package, versions <0:3.7.2-1.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.32% (22nd percentile)

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  • Snyk IDSNYK-AMZN2023-LIBSOUP3DEVEL-20249256
  • published29 Sept 2026
  • disclosed4 Sept 2026

Introduced: 4 Sep 2026

NewCVE-2026-85534  (opens in a new tab)
CWE-617  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 libsoup3-devel to version 0:3.7.2-1.amzn2023 or higher.
This issue was patched in ALAS2023-2026-3144.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libsoup3-devel package and not the libsoup3-devel package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1