Cyber Resilience

CVE-2026-21996

Oracle Linux 10 … 9

Published
01 May 2026
Modified
05 May 2026
Patch / advisory
CVSS Score v3.1 3.3
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:L
EPSS Score 0.0011 1th percentile
Risk Priority 15 floored blend · peak EPSS

Summary

CVE-2026-21996 is a low-severity Divide By Zero (CWE-369) vulnerability in Oracle Linux. Its CVSS base score is 3.3 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 1th 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 AC-6 (Least Privilege) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

An unprivileged attacker can reliably trigger a crash of the dtrace process with a malicious ELF binary due to an integer Divide-by-Zero in Pbuild_file_symtab()

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Divide-by-zero in dtrace triggered by malicious ELF binary directly enables local application DoS via exploitation (T1499.004).

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

CVEs Like This One

CVE-2026-21991Same product: Oracle Linux
CVE-2026-35233Same product: Oracle Linux
CVE-2026-22009Same vendor: Oracle
CVE-2026-46936Same vendor: Oracle
CVE-2026-61147Same vendor: Oracle
CVE-2026-47012Same vendor: Oracle
CVE-2026-60189Same vendor: Oracle
CVE-2026-60174Same vendor: Oracle
CVE-2026-47062Same vendor: Oracle
CVE-2026-60191Same vendor: Oracle

Affected Assets

oracle
linux
10, 8, 9

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • AC-6 Least Privilege
  • SC-39 Process Isolation
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces validation of ELF binary inputs to Pbuild_file_symtab() to reject malformed data that triggers the divide-by-zero.

prevent

Restricts unprivileged users from invoking dtrace against arbitrary ELF binaries, limiting exposure to the vulnerable code path.

prevent

Isolates the dtrace process so a divide-by-zero crash cannot affect other system components or escalate impact.

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 include code analysis, input validation, and testing that prevent divide-by-zero errors.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover divide-by-zero flaws via static analysis or testing.

PR.PS-02 partial match
prevents

Routine patching and replacement can remediate divide-by-zero bugs present 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.

detects

Security testing in development can detect divide-by-zero conditions before release.

prevents

Secure development lifecycle includes input validation and error-handling practices that can prevent divide-by-zero faults.

prevents

Application security requirements can mandate checks for zero denominators and safe arithmetic handling.

prevents

Secure architecture principles encourage defensive coding patterns that avoid arithmetic exceptions.

prevents

Secure coding standards directly require validation to prevent divide-by-zero and similar runtime faults.

References