Skip to main content

libsoup EUVDEUVD-2026-70997

| CVE-2026-85534 MEDIUM
Reachable Assertion (CWE-617)
2026-09-04 redhat GHSA-qm5f-xr9c-mm27
Red Hat Red Hat Enterprise Linux 10 Red Hat Enterprise Linux 6 Red Hat Enterprise Linux 7 Red Hat Enterprise Linux 8 Red Hat Enterprise Linux 9 Suse Red Hat
5.9
CVSS 3.1 · Vendor: redhat
Share

Severity by source

Vendor (redhat) PRIMARY
5.9 MEDIUM
AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
vuln.today AI
5.9 MEDIUM

Network-reachable via malicious server (AV:N), but requires precise timing of SETTINGS shrink against non-pollable stream buffer (AC:H); impact is process abort only (A:H, C:N, I:N).

3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
4.0 AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
SUSE
8.1 HIGH
AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Red Hat
5.9 MEDIUM
qualitative

Primary rating from Vendor (redhat).

CVSS VectorVendor: redhat

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Lifecycle Timeline

3
Metadata Corrected
Sep 04, 2026 - 11:40 vuln.today
tag: Information Disclosure removed
Analysis Generated
Sep 04, 2026 - 10:51 vuln.today
CVE Published
Sep 04, 2026 - 10:19 cve.org
MEDIUM 5.9

DescriptionCVE.org

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.

AnalysisAI

HTTP/2 flow-control window mismanagement in libsoup (GNOME's HTTP client/server library) allows a malicious HTTP/2 server to abort a connecting client process or crash its HTTP/2 session. When the client sends a request body sourced from a non-pollable GInputStream, libsoup buffers the data before transmission; a server that then shrinks SETTINGS_INITIAL_WINDOW_SIZE causes the client to copy the full pre-buffered payload into a now-undersized DATA callback without a runtime bounds check, triggering a reachable assertion abort (CWE-617). …

Unlock full vulnerability intelligence

  • Risk assessment & exploitation conditions
  • Attack chain visualization
  • Remediation with exact patch versions
  • Threat intelligence from 22 sources
  • Personal watchlist & email alerts
Continue with Google Continue with GitHub

Free forever · No credit card required

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access
technique details hidden
Delivery
technique details hidden
Exploit
technique details hidden
Execution
technique details hidden
Persist
technique details hidden
Impact
technique details hidden
Sign in to reveal

Vulnerability AssessmentAI

Exploitation Exploitation requires the following specific conditions to align simultaneously: (1) the client must be communicating over HTTP/2, not HTTP/1.x; (2) the HTTP/2 request must include a body provided via a non-pollable GInputStream - a specific GLib I/O stream type that cannot be monitored by polling - causing libsoup to buffer the payload; (3) the client must connect to an attacker-controlled or attacker-influenced HTTP/2 server capable of issuing a SETTINGS frame with a reduced SETTINGS_INITIAL_WINDOW_SIZE; and (4) the server must time this SETTINGS frame while the buffered read is still unresolved. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment The CVSS 5.9 (AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H) accurately captures the constrained exploitation surface: triggering the race requires the server to shrink SETTINGS_INITIAL_WINDOW_SIZE at the precise moment between buffer fill and DATA callback execution, making reliable exploitation non-trivial. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario Full exploit scenario with step-by-step reproduction available after sign-in.
Remediation No vendor-released patch with an exact fix version has been identified at time of analysis. … Detailed patch versions, workarounds, and compensating controls in full report.
Sign in to read full assessment

Threat intelligence, references, and detailed analysis are available after sign-in.

More in Red Hat Enterprise Linux 10

View all
CVE-2026-18663 MEDIUM
5.9 Aug 12

Heap corruption via double-free in 389-ds-base's LDAP control parsing allows an unauthenticated remote attacker to crash
CVE-2026-4631 CRITICAL POC
9.8 Apr 07

Remote code execution in Cockpit's web interface allows unauthenticated attackers to execute arbitrary commands on the h
CVE-2026-4480 CRITICAL POC
9.0 May 26

Remote code execution in Samba's printing subsystem allows remote attackers to inject arbitrary shell commands via craft
CVE-2026-18922 CRITICAL
9.8 Sep 07

Authentication bypass in 389 Directory Server (shipped as Red Hat Directory Server 11-13 and within RHEL 6-10) lets remo
CVE-2026-14544 CRITICAL
9.8 Jul 03

Remote code execution and privilege escalation in HPLIP (HP Linux Imaging and Printing) affects the hpcups print filter

CVE-2026-76578 CRITICAL
9.8 Sep 07

Unauthenticated privilege escalation in FreeIPA (Red Hat Identity Management) allows a remote attacker to gain genuine a
CVE-2026-5121 HIGH
7.5 Mar 30

Remote code execution in libarchive on 32-bit systems allows unauthenticated attackers to execute arbitrary code via spe
CVE-2026-28369 CRITICAL
9.1 Mar 27

HTTP request smuggling in Undertow (the embedded web server underpinning JBoss EAP, Red Hat Data Grid, and Apache Camel

CVE-2026-28368 CRITICAL
9.1 Mar 27

HTTP request smuggling in Red Hat Undertow allows remote unauthenticated attackers to bypass front-end security controls
CVE-2026-33845 CRITICAL
9.1 Apr 30

Out-of-bounds read in the GnuTLS DTLS handshake reassembly logic lets remote unauthenticated attackers trigger an intege
CVE-2026-28367 CRITICAL
9.1 Mar 27

HTTP request smuggling in Undertow allows remote unauthenticated attackers to send `\r\r\r` as a header block terminator
CVE-2026-16526 HIGH
8.8 Jul 30

Local privilege escalation in Performance Co-Pilot (PCP) on Red Hat Enterprise Linux 6 through 10 and OpenShift Containe

Same weakness CWE-617 – Reachable Assertion

View all
CVE-2025-15684 MEDIUM POC
5.5
CVE-2016-8864 HIGH
7.5
CVE-2020-12417 HIGH POC
8.8
CVE-2020-6623 HIGH POC
8.8
CVE-2020-6619 HIGH POC
8.8
CVE-2020-6617 HIGH POC
8.8
CVE-2023-37023 HIGH POC
8.6
CVE-2023-37021 HIGH POC
8.6

Vendor StatusVendor

SUSE

Severity: Important
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise Desktop 15 SP7 Not-Affected
SUSE Linux Enterprise Micro 5.3 Not-Affected
SUSE Linux Enterprise Micro 5.4 Not-Affected
SUSE Linux Enterprise Micro 5.5 Not-Affected

Share

EUVD-2026-70997 vulnerability details – vuln.today
Back

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy