Gnutls: gnutls: denial of service via dtls zero-length fragment

Summary

CVE	CVE-2026-33845
State	PUBLISHED
Assigner	redhat
Source Priority	CVE Program / NVD first with legacy fallback
Published	2026-04-30 18:16:28 UTC
Updated	2026-06-01 21:16:41 UTC
Description	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.

Risk And Classification

Primary CVSS: v3.1 9.1 CRITICAL from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

EPSS: 0.000590000 probability, percentile 0.187750000 (date 2026-05-31)

Problem Types: CWE-191 | CWE-191 Integer Underflow (Wrap or Wraparound)

Version	Source	Type	Score	Severity	Vector
3.1	[email protected]	Primary	9.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`
3.1	[email protected]	Secondary	7.5	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`
3.1	CNA	CVSS	7.5	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`

CVSS v3.1 Breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

Type	Vendor	Product	Version	Update	Edition	Language
Application	Gnu	Gnutls	-	All	All	All
Operating System	Redhat	Enterprise Linux	10.0	All	All	All
Operating System	Redhat	Enterprise Linux	6.0	All	All	All
Operating System	Redhat	Enterprise Linux	7.0	All	All	All
Operating System	Redhat	Enterprise Linux	8.0	All	All	All
Operating System	Redhat	Enterprise Linux	9.0	All	All	All
Application	Redhat	Openshift Container Platform	4.0	All	All	All

Vendor Declared Affected Products

Source	Vendor	Product	Version	Platforms
CNA	Red Hat	Red Hat Enterprise Linux 10	unaffected 0:3.8.10-4.el10_2 * rpm	Not specified
CNA	Red Hat	Red Hat Enterprise Linux 8	unaffected 0:3.6.16-8.el8_10.6 * rpm	Not specified
CNA	Red Hat	Red Hat Enterprise Linux 8	unaffected 0:3.6.16-8.el8_10.6 * rpm	Not specified
CNA	Red Hat	Red Hat Hardened Images	unaffected 3.8.13-1.hum1 * rpm	Not specified
CNA	Red Hat	Red Hat Enterprise Linux 6	Not specified	Not specified
CNA	Red Hat	Red Hat Enterprise Linux 7	Not specified	Not specified
CNA	Red Hat	Red Hat Enterprise Linux 9	Not specified	Not specified
CNA	Red Hat	Red Hat OpenShift Container Platform 4	Not specified	Not specified

References

Reference	Source	Link	Tags
access.redhat.com/errata/RHSA-2026:13274	[email protected]	access.redhat.com	Vendor Advisory
access.redhat.com/security/cve/CVE-2026-33845	[email protected]	access.redhat.com	Vendor Advisory
access.redhat.com/errata/RHSA-2026:20613	[email protected]	access.redhat.com
bugzilla.redhat.com/show_bug.cgi	[email protected]	bugzilla.redhat.com	Issue Tracking, Vendor Advisory
access.redhat.com/errata/RHSA-2026:20611	[email protected]	access.redhat.com
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

No vendor comments have been submitted for this CVE.

Additional Advisory Data

Source	Time	Event
CNA	2026-03-24T05:35:59.740Z	Reported to Red Hat.
CNA	2026-04-30T17:28:41.473Z	Made public.

Workarounds

CNA: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

There are currently no legacy QID mappings associated with this CVE.