What’s Vulnerable › Vulnerabilities

CVE-2026-103963: Glib-networking: unbounded tls 1.3 session ticket queue growth in glib-networking allows remote denial of service

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-30 · updated 2026-10-30
• Weakness: CWE-400

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 products

• Red Hat Enterprise Linux 10: all versions
• Red Hat Enterprise Linux 9: all versions

References

• https://access.redhat.com/security/cve/CVE-2026-103963
• https://bugzilla.redhat.com/show_bug.cgi?id=2465656
• https://gitlab.gnome.org/GNOME/glib-networking/-/merge_requests/288

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