What is CVE-2026-103963?

CVE-2026-103963 is a high-severity vulnerability in Red Hat Enterprise Linux 10, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-10-30.

How severe is CVE-2026-103963?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Red Hat Enterprise Linux 10

CVE-2026-103963

A flaw was found in glib-networking. When establishing connections using Transport Layer Security (TLS) version 1.3, the client-side session cache does not limit the number of session tickets retained for a single host. A malicious server can exploit this by sending excessive session ticket messages, causing the client application to continuously consume memory. This unbounded memory growth can exhaust system memory, resulting in a Denial of Service (DoS).

Vulnerability class: DoS (Denial of Service)

Published 2026-10-30 · last modified 2026-10-30.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.003 (27.3th percentile), scored 2026-10-31.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 27.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

References

access.redhat.com/security/cve/CVE-2026-103963 (vdb-entry)
bugzilla.redhat.com/show_bug.cgi (issue-tracking)
gitlab.gnome.org/GNOME/glib-networking/-/merge_requests/288

Frequently asked questions

What is CVE-2026-103963?: CVE-2026-103963 is a high-severity vulnerability in Red Hat Enterprise Linux 10, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-10-30.
How severe is CVE-2026-103963?: High severity. CVSS v3 base score is 7.5 out of 10.