CVE-2026-102558

Libsoup: libsoup: heap buffer overflow during websocket receive-buffer growth

HIGH
8.6
CVSS Score
Published: September 29, 2026 at 05:15 PM UTC
Updated: October 29, 2026 at 08:17 PM UTC
2 products affected across 2 vendorsEnterprise LinuxLibsoup

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Severity
HIGH8.6
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

Description

A flaw was found in libsoup. When max-incoming-payload-size is unlimited (0), SoupWebsocketConnection could grow its incoming GByteArray based on an attacker-controlled frame length until the length wrapped, causing a heap buffer overflow while reading frame data.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 3.7.3
Vendor states this is fixed in 0:2.62.3-19.el8_10 (unaffected)
Vendor states this is fixed in 0:2.72.0-16.el9_8.8 (unaffected)
Vendor states this is fixed in 0:3.6.5-3.el10_2.20 (unaffected)
Vendor states this is fixed in 6 (unknown)

References (6)

VDB Entryx_refsource_REDHATMitigationVendor Advisory
Source: cverecord
https://access.redhat.com/security/cve/CVE-2026-102558
Issue Trackingx_refsource_REDHATVendor Advisory
Source: cverecord
https://bugzilla.redhat.com/show_bug.cgi?id=2543274
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:83384
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:83618
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:84586
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:92347

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.6HIGHredhat
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-125

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