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CVE-2026-33846 Detail

Description

A heap buffer overflow vulnerability exists in the DTLS handshake fragment reassembly logic of GnuTLS. The issue arises in merge_handshake_packet() where incoming handshake fragments are matched and merged based solely on handshake type, without validating that the message_length field remains consistent across all fragments of the same logical message. An attacker can exploit this by sending crafted DTLS fragments with conflicting message_length values, causing the implementation to allocate a buffer based on a smaller initial fragment and subsequently write beyond its bounds using larger, inconsistent fragments. Because the merge operation does not enforce proper bounds checking against the allocated buffer size, this results in an out-of-bounds write on the heap. The vulnerability is remotely exploitable without authentication via the DTLS handshake path and can lead to application crashes or potential memory corruption.


Metrics

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CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

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URL Source(s) Tag(s)
https://access.redhat.com/errata/RHSA-2026:13274 Red Hat, Inc.
https://access.redhat.com/security/cve/CVE-2026-33846 Red Hat, Inc.
https://bugzilla.redhat.com/show_bug.cgi?id=2450625 Red Hat, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-130 Improper Handling of Length Parameter Inconsistency Red Hat, Inc.  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-33846
NVD Published Date:
05/04/2026
NVD Last Modified:
05/04/2026
Source:
Red Hat, Inc.