Busybox 1.38.0 Shell shell/ash.c evalcommand heap-based overflow

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.5$0-$5k0.59

Summaryinfo

A vulnerability, which was classified as critical, was found in Busybox 1.38.0. The impacted element is the function evalcommand of the file shell/ash.c of the component Shell. Such manipulation leads to heap-based overflow. This vulnerability is referenced as CVE-2026-38755. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability was found in Busybox 1.38.0. It has been rated as critical. Affected by this issue is the function evalcommand of the file shell/ash.c of the component Shell. The manipulation with an unknown input leads to a heap-based overflow vulnerability. Using CWE to declare the problem leads to CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). Impacted is availability. CVE summarizes:

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.

This vulnerability is handled as CVE-2026-38755 since 04/06/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 07/15/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.5

VulDB Base Score: 6.5
VulDB Temp Score: 6.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

04/06/2026 CVE reserved
07/15/2026 +100 days Advisory disclosed
07/15/2026 +0 days VulDB entry created
07/15/2026 +0 days VulDB entry last update

Sourcesinfo

Status: Not defined

CVE: CVE-2026-38755 (🔒)
GCVE (CVE): GCVE-0-2026-38755
GCVE (VulDB): GCVE-100-379430

Entryinfo

Created: 07/15/2026 23:56
Changes: 07/15/2026 23:56 (52)
Complete: 🔍
Cache ID: 216::103

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