Vulnerability · Published Oct 30, 2026 · Assigned by redhat
CVE-2026-103963Glib-networking: unbounded tls 1.3 session ticket queue growth in glib-networking allows remote denial of service
High 7.5
In plain English
A high-severity uncontrolled resource consumption in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities).
Official description
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).
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | glib-networking | no fix listed | DEBIAN-CVE-2026-103963 |
| Debian:13 | glib-networking | no fix listed | DEBIAN-CVE-2026-103963 |
| Debian:14 | glib-networking | no fix listed | DEBIAN-CVE-2026-103963 |
| Ubuntu:22.04:LTS | glib-networking | no fix listed | UBUNTU-CVE-2026-103963 |
| Ubuntu:24.04:LTS | glib-networking | no fix listed | UBUNTU-CVE-2026-103963 |
| Ubuntu:26.04:LTS | glib-networking | no fix listed | UBUNTU-CVE-2026-103963 |
| Ubuntu:26.10 | glib-networking | no fix listed | UBUNTU-CVE-2026-103963 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | see references |
| Red Hat | Red Hat Enterprise Linux 6 | see references |
| Red Hat | Red Hat Enterprise Linux 7 | see references |
| Red Hat | Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
Weakness: CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://access.redhat.com/security/cve/CVE-2026-103963 vdb-entry, x_refsource_REDHAT
- RHBZ#2465656 issue-tracking, x_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/glib-networking/-/merge_requests/288