libsoup Wraps Size Values When Masking Large Outgoing WebSocket Client Frames, Causing Heap Overflow During Message Send
Last refreshed2026-10-30
Status: UPDATED
| Advisory ID: CVE-2026-102559
Key Details
CVE
CVE-2026-102559
CVSS Score / Version
8.6 (High) / CVSS v3.1
Updated
2026-10-29
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
CVSS Prose
attack vector is network; attack complexity is low; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is low; integrity impact is low; availability impact is high.
Affected products
Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, and Red Hat Enterprise Linux 7
Classified as
CWE-125 (Out-of-bounds Read)
Exploitation prediction (EPSS)
0.38% probability of exploitation in the next 30 days (30% percentile) -- FIRST.org's EPSS model.
Affected Products, Subsystems & Sectors
Vendor
Product
Affected Versions
Patch Status
Red Hat
Red Hat Enterprise Linux 10
Red Hat
Red Hat Enterprise Linux 8
Red Hat
Red Hat Enterprise Linux 9
Red Hat
Red Hat Enterprise Linux 7
Subsystems
OT Supporting Infrastructure
Sectors
Multiple
What to Know
A flaw was found in libsoup. When constructing a masked WebSocket client frame for a very large outgoing payload, size values passed to GByteArray allocation APIs could be truncated while the masking routine still used the full length, causing a heap buffer overflow. (NVD)
What to Do
Monitor Red Hat's web page for any future patch releases.