Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2026-31931 is a high-severity NULL Pointer Dereference (CWE-476) vulnerability in Oisf Suricata. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 28th percentile by exploit likelihood (below the median); 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-15 (Development Process, Standards, and Tools) — 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-2026-31931 is a NULL dereference vulnerability in Suricata, an open-source network intrusion detection system (IDS), intrusion prevention system (IPS), and network security monitoring (NSM) engine. The issue affects versions 8.0.0 through 8.0.3, where use of the "tls.alpn" rule keyword during rule evaluation triggers a crash. Classified under CWE-476 (NULL Pointer Dereference), 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), indicating high availability impact with no effects on confidentiality or integrity.
Attackers can exploit this vulnerability remotely over the network with low complexity, requiring no privileges or user interaction. By crafting network traffic that matches a Suricata rule using the "tls.alpn" keyword—such as TLS traffic with a specific Application-Layer Protocol Negotiation (ALPN) extension—any unauthenticated adversary reachable by the Suricata sensor can trigger the NULL dereference, causing the engine to crash and potentially leading to denial-of-service (DoS) on monitored traffic.
The vulnerability has been addressed in Suricata version 8.0.4, as detailed in the official GitHub security advisory (GHSA-gr22-4784-xvw3) and OISF Redmine issue #8294. Security practitioners should upgrade to 8.0.4 or later and review rulesets for "tls.alpn" usage, temporarily disabling affected rules if immediate patching is not feasible.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-18237
Vulnerability Data
Suricata is a network IDS, IPS and NSM engine. From version 8.0.0 to before version 8.0.4, use of the "tls.alpn" rule keyword can cause Suricata to crash with a NULL dereference. This issue has been patched in version 8.0.4.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (including static analysis) directly finds null-dereference bugs before deployment.
Documented development standards and tools can enforce null-safety rules and safe pointer usage.
Engineering principles can mandate defensive coding such as explicit null checks before dereference.
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 (static analysis, code review, safe coding standards) directly prevent NULL dereference bugs during development.
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 can detect NULL dereference defects before release.
Secure SDLC mandates defensive coding practices that can prevent NULL dereferences.
Application security requirements can specify input validation and pointer-safety rules.
Secure architecture principles encourage defensive design that avoids unsafe pointer use.
Secure coding standards directly require NULL-pointer checks and safe dereference patterns.