# CVE-2026-103963: glib-networking unbounded memory consumption in TLS 1.3

Source: https://junglewise.ai/threats/cve-2026-103963-a-flaw-was-found-in-glib-networking-when-establishing  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-30. Updated: 2026-10-30  
License: CC BY 4.0 with a link back

CVE-2026-103963 · Severity: high · CVSS 7.5 · Published 2026-10-30

glib-networking is a library that handles secure network connections for many Linux applications. When using TLS 1.3 encryption, a malicious server can send excessive session tickets to exhaust a client's memory, causing the application to crash or become unresponsive. This affects any application using glib-networking to establish secure connections.

Technologies: [Gnome Glib-Networking](https://junglewise.ai/threats/technologies/glib-networking). Vendors: [Gnome](https://junglewise.ai/threats/vendors/gnome).

## Quick answers

**Is CVE-2026-103963 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-103963 being exploited in the wild.

**How severe is CVE-2026-103963?** High severity, with a CVSS score of 7.5, published 30 October 2026.

**Which products and versions are affected?** Gnome Glib-Networking <UNKNOWN>.

**Is there a fix for CVE-2026-103963?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-103963 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-103963?** Check whether you run Gnome Glib-Networking at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is an uncontrolled resource consumption flaw (CWE-400) in the TLS 1.3 session ticket handling code. The client-side session cache fails to enforce limits on the number of session tickets retained per host, allowing a remote attacker to send excessive tickets and trigger unbounded memory allocation. Attack requires no authentication or user interaction, only a network connection to a malicious TLS server.

## Affected products

- GNOME glib-networking <UNKNOWN>

## Timeline

- 2026-10-30: disclosed

## References

- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/security/cve/CVE-2026-103963](https://access.redhat.com/security/cve/CVE-2026-103963)

## Related threats

- [GNOME glib-networking infinite loop in GnuTLS certificate verification](https://junglewise.ai/threats/cve-2026-10028-gnome-glib-networking-infinite-loop-in-gnutls-certificate)
- [GNOME glib-networking uninitialized pointer dereference in OpenSSL backend](https://junglewise.ai/threats/cve-2025-60019-gnome-glib-networking-uninitialized-pointer-dereference-in)
- [GNOME glib-networking out of bounds read in OpenSSL backend](https://junglewise.ai/threats/cve-2025-60018-gnome-glib-networking-out-of-bounds-read-in-openssl-backend)