CVE-2026-33846
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2026-33846 is a high-severity Improper Handling of Length Parameter Inconsistency (CWE-130) vulnerability in Redhat (inferred from references). Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 33% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
A heap buffer overflow vulnerability, tracked as CVE-2026-33846, exists in the DTLS handshake fragment reassembly logic of GnuTLS. The flaw occurs in the merge_handshake_packet() function, 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 due to inadequate bounds checking against the allocated buffer size.
This vulnerability is remotely exploitable without authentication via the DTLS handshake path by any network attacker. Exploitation involves sending specially crafted DTLS fragments, leading to out-of-bounds writes on the heap that can result in application crashes or potential memory corruption. It carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) and is associated with CWE-130 (Improper Handling of Length Parameter Inconsistency).
Red Hat has issued errata RHSA-2026:13274 to address the issue. Further details on the vulnerability and remediation are available via the Red Hat security advisory at https://access.redhat.com/security/cve/CVE-2026-33846 and Bugzilla entry https://bugzilla.redhat.com/show_bug.cgi?id=2450625.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-26926
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V3.5.5V4.2.1V4.2.2
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover length-parameter inconsistencies through targeted parsing tests.
Input validation enforces correct length-to-data consistency checks on parsed messages before processing.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly enforce length validation and input sanitization during coding and review.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect length-inconsistency vulnerabilities before deployment.
Secure development lifecycle mandates input validation and length checks that directly address inconsistent length fields.
Application security requirements include explicit rules for handling message lengths and data structures.
Secure architecture principles require robust parsing and bounds checking to prevent length-related flaws.
Secure coding standards directly prohibit improper length handling and enforce defensive parsing practices.