Cyber Resilience

CVE-2026-33845

Memory Safety in Redhat Enterprise Linux 10.0 … 9.0

Published
30 April 2026
Modified
20 July 2026
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0080 54th percentile
Risk Priority 59 floored blend · peak EPSS

Summary

CVE-2026-33845 is a high-severity Wrap or Wraparound (CWE-191) vulnerability in Redhat Enterprise Linux. 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 46% 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 SA-8 (Security and Privacy Engineering Principles) — 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.

CVE-2026-33845 is a vulnerability in the GnuTLS library's DTLS handshake parsing mechanism. The flaw enables the processing of malformed fragments that have zero length but a non-zero offset, triggering an integer underflow (CWE-191) during reassembly and resulting in an out-of-bounds read. This issue affects GnuTLS implementations that handle DTLS traffic.

The vulnerability 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), indicating network-based exploitation with low complexity, no privileges or user interaction required. Unauthenticated remote attackers can send crafted DTLS handshake packets to vulnerable GnuTLS instances, potentially causing information disclosure or denial of service through the out-of-bounds read.

Red Hat has documented the issue in security advisories and provides related details in their CVE page at https://access.redhat.com/security/cve/CVE-2026-33845 and Bugzilla tracker at https://bugzilla.redhat.com/show_bug.cgi?id=2450624, where mitigation guidance such as patches or workarounds may be available.

EU & UK References

Vulnerability Data

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…

more

denial of service.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-32990Same product: Gnu Gnutls
CVE-2025-32988Same product: Gnu Gnutls
CVE-2026-42010Same product: Gnu Gnutls
CVE-2025-32989Same product: Gnu Gnutls
CVE-2026-3832Same product: Gnu Gnutls
CVE-2026-3442Same product: Redhat Enterprise Linux
CVE-2026-4647Same product: Redhat Enterprise Linux
CVE-2026-3441Same product: Redhat Enterprise Linux
CVE-2026-6846Same product: Redhat Enterprise Linux
CVE-2025-0678Same product: Redhat Enterprise Linux

Affected Assets

gnu
gnutls
all versions
redhat
openshift container platform
4.0
redhat
enterprise linux
10.0, 6.0, 7.0, 8.0, 9.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and static/dynamic analysis directly find integer underflow defects before code is released.

Security engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer underflow during subtraction.

Input validation can reject or sanitize values that would cause a subtraction to underflow the representable range.

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.

PR.PS-06 full match
prevents

Secure SDLC practices directly prevent integer underflow defects via input validation, bounds checking, and static analysis.

ID.RA-01 partial match
prevents

Vulnerability scanning and code analysis can surface underflow flaws after they are introduced.

PR.PS-02 partial match
prevents

Routine patching can remediate known underflow bugs once they are discovered in deployed software.

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.

finds

Security testing in development catches integer underflow defects before release.

prevents

Secure development lifecycle mandates input validation and arithmetic checks that prevent integer underflow.

prevents

Application security requirements include bounds checking and safe arithmetic to avoid underflow conditions.

prevents

Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.

prevents

Secure coding standards directly prescribe safe integer handling and overflow/underflow prevention.

References