Cyber Resilience

CVE-2026-38755

Memory Safety in Busybox 1.38.0

Memory SafetyDoS
Published
15 July 2026
Modified
20 July 2026
Patch / advisory
View advisory
CVSS Score v3.1 2.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS Score 0.0021 11th percentile
Risk Priority 26 floored blend · peak EPSS

Summary

CVE-2026-38755 is a low-severity Uncontrolled Recursion (CWE-674) vulnerability in Busybox Busybox. Its CVSS base score is 2.9 (Low).

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

EU & UK References

Vulnerability Data

A heap overflow in the evalcommand() function (shell/ash.c) of Busybox v1.38.0 allows attackers to cause a Denial of Service (DoS) via supplying a crafted input.

CWE(s)
CWE-674CWE-122

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.
attack.mitre.org →
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.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-38752Same product: Busybox Busybox
CVE-2026-38754Same product: Busybox Busybox
CVE-2023-42365Same product: Busybox Busybox
CVE-2023-42363Same product: Busybox Busybox
CVE-2026-38753Same product: Busybox Busybox
CVE-2023-42364Same product: Busybox Busybox
CVE-2023-42366Same product: Busybox Busybox
CVE-2023-39810Same product: Busybox Busybox
CVE-2025-60876Same product: Busybox Busybox
CVE-2025-46394Same product: Busybox Busybox

Affected Assets

busybox
busybox
1.38.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.4.1

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation (including fuzzing and memory-error detectors) can discover heap overflows after they have been coded.

SI-10 Information Input Validation good match

Input validation can reject or constrain data that would otherwise drive unbounded recursive calls.

SA-8 Security and Privacy Engineering Principles partial match

Security engineering principles require use of memory-safe constructs and bounds-checked allocation routines that avoid introducing heap overflows.

SC-5 Denial-of-service Protection partial match

DoS protection mechanisms limit the resource-exhaustion impact of uncontrolled recursion without eliminating the flaw.

SI-16 Memory Protection partial match

Memory-protection mechanisms limit the ability of a heap overflow to execute attacker-controlled code or corrupt adjacent structures.

SI-4 System Monitoring partial match

System monitoring can observe anomalous resource consumption that signals runaway recursion after it begins.

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-development practices directly require bounds checking and safe memory handling that prevent heap overflows.

DE.CM-09 partial match
prevents

Runtime monitoring of compute resources can detect excessive consumption caused by uncontrolled recursion.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover and record uncontrolled recursion flaws before deployment.

PR.IR-04 partial match
prevents

Capacity monitoring and resource provisioning can absorb or limit the impact of runaway recursion.

PR.PS-02 partial match
prevents

Timely patching removes known heap-overflow instances after they exist.

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.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development can detect excessive recursion via static analysis or fuzzing.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle requires controls that prevent uncontrolled recursion through design and code review.

A.8.26 Application security requirements partial match
prevents

Application security requirements can mandate recursion limits or stack-depth checks.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure system architecture principles include resource-management and input-validation rules that limit recursion.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly prohibit or constrain recursive constructs that could exhaust stack or memory.

A.8.6 Capacity management partial match
finds

Capacity management includes monitoring and limits that mitigate resource exhaustion from runaway recursion.

References