CVE-2026-33845

A flaw in GnuTLS DTLS handshake parsing allows malformed fragments with zero length and non-zero offset, leading to an integer underflow during reassembly and resulting in an out-of-bounds read. This issue is remotely exploitable and may cause information disclosure or denial of service.

What this means for your business

It affects Gnutls. It matters if your company, or a supplier that handles your data, runs it.
An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
FIRST's prediction model gives it a 0.8% chance of attack attempts being seen in the next 30 days, ranking above 54% of all known flaws.

What to do

1Check whether your company or your suppliers run Gnutls, and which version. The affected versions are listed further down this page.
2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

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Scoring

CVSS: 7.5 (v3.1)
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-191
Assigned by: secalert@redhat.com

Dates

Published: 2026-04-30
Last modified: 2026-09-18
Sources: NVD

Affected products

Gnu Gnutlsall versions
Redhat Openshift Container Platform4.0
Redhat Enterprise Linux6.0, 7.0, 8.0, 9.0, 10.0

As listed in the NVD configuration data. Not a statement about your estate.