Cyber Resilience

CVE-2026-31491

Memory Safety in Linux Kernel 6.18.1 – 6.18.21

Published
22 April 2026
Modified
28 April 2026
Patch / advisory
CVSS Score v3.1 5.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0012 2th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-31491 is a medium-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Linux Linux Kernel. Its CVSS base score is 5.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 2th 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 SI-10 (Information Input Validation) and SA-11 (Developer Testing and Evaluation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

In the Linux kernel, the following vulnerability has been resolved: RDMA/irdma: Harden depth calculation functions An issue was exposed where OS can pass in U32_MAX for SQ/RQ/SRQ size. This can cause integer overflow and truncation of SQ/RQ/SRQ depth returning a…

more

success when it should have failed. Harden the functions to do all depth calculations and boundary checking in u64 sizes.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
Why these techniques?

Integer overflow (CWE-190) in kernel RDMA driver depth checks allows invalid queue sizes to succeed, directly enabling local exploitation for privilege escalation via memory corruption or bypass of security boundaries.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

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CVE-2026-52972Same product: Linux Linux Kernel
CVE-2026-31648Same product: Linux Linux Kernel
CVE-2026-46023Same product: Linux Linux Kernel
CVE-2026-53068Same product: Linux Linux Kernel
CVE-2026-46039Same product: Linux Linux Kernel
CVE-2026-31641Same product: Linux Linux Kernel

Affected Assets

linux
linux kernel
6.18, 7.0 · 6.18.1 — 6.18.21 · 6.19 — 6.19.11

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • SA-11 Developer Testing and Evaluation
  • SA-15 Development Process, Standards, and Tools
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V5.2.6

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces validation of untrusted size parameters (SQ/RQ/SRQ depth) before arithmetic to block U32_MAX values that trigger CWE-190 overflow.

prevent

Requires developer testing and static/dynamic analysis that would detect integer-overflow paths in depth-calculation routines during RDMA driver development.

prevent

Mandates secure development standards and tools (safe integer types, bounds-checked arithmetic) that prevent truncation bugs when hardening irdma depth functions.

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 mostly match
prevents

Secure SDLC practices directly require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.

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.

detects

Security testing in development can detect integer overflows before release.

prevents

Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.

degrades

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

degrades

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

prevents

Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.

References