CVE-2026-102559

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.

CVSS 3.1

8.6CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

EPSS

0.4% chance of exploitation in the next 30 days; higher than 34% of CVEs (scores of 2026-10-25)

CWE

CWE-125

Published

2026-09-29

Modified

2026-10-19

Record from

the NVD, synced 2026-10-19

Affected

• gnome:libsoup
• redhat:enterprise_linux

References

• https://access.redhat.com/errata/RHSA-2026:83384
• https://access.redhat.com/errata/RHSA-2026:83618
• https://access.redhat.com/errata/RHSA-2026:84586
• https://access.redhat.com/security/cve/CVE-2026-102559
• https://bugzilla.redhat.com/show_bug.cgi?id=2543285

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