VulnerabilityPublished 4 Feb 2026

CVE-2026-24844: chainguard-dev melange · OS Command Injection

Affects chainguard-dev melangeSource CVE Database V5

Not known to be exploited · CVSS 7.8 High : upgrade to 0.40.3 soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

7.8High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.40.3, 0.40.0

CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: Required
Scope: Changed
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade melange to 0.40.3; chainguard-dev/melange to 0.40.0.

Affected software

Product	Affected	Fixed in
chainguard-devmelange	Affected >=0.3.0 <0.40.3	Fixed in 0.40.3
GitHubchainguard-dev/melange`pkg:github/chainguard-dev/melange`Other threats	Affected <0.40.0	Fixed in 0.40.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

European organizations should immediately upgrade melange to version 0.40.3 or later to apply the official patch that addresses this vulnerability. Until upgrading, organizations should avoid using untrusted or user-supplied input in the working-directory field or any shell-invoked pipeline parameters. Implement strict input validation and sanitization for all build inputs, especially those that influence shell commands or environment variables. Employ least privilege principles for build system users to limit the ability of attackers to supply malicious inputs. Monitor build logs and pipeline executions for anomalous command executions or unexpected shell activity. Consider isolating build environments using containerization or sandboxing to reduce the blast radius of potential exploitation. Finally, integrate security scanning and static analysis tools into the CI/CD pipeline to detect unsafe shell usage patterns.

Description

CVE-2026-24844 is a high-severity OS command injection vulnerability in chainguard-dev's melange tool versions 0.3.0 up to but not including 0.40.3. The flaw arises when user-controlled input values are substituted into the working-directory field of declarative build pipelines without proper shell escaping, allowing attackers with limited privileges to execute arbitrary shell commands. Exploitation requires the attacker to provide build input values and involves user interaction, but does not require modification of pipeline definitions. The vulnerability impacts confidentiality and integrity but not availability. It has been patched in version 0.40.

Impact

For European organizations, this vulnerability poses a significant risk especially to those using melange in their build pipelines for Android APK packaging. Successful exploitation could lead to unauthorized command execution within the build environment, potentially exposing sensitive build artifacts, leaking confidential information, or corrupting the integrity of software packages. This could undermine software supply chain security, leading to downstream compromise of applications distributed to end users. Organizations involved in mobile app development, software supply chain management, or those relying on automated build systems are particularly at risk. The impact is amplified in regulated industries or sectors with strict software integrity requirements, such as finance, healthcare, and critical infrastructure. Additionally, the vulnerability could be leveraged for lateral movement or persistence if the build environment is connected to broader enterprise networks.

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #9OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
Architecture and Design
If at all possible, use library calls rather than external processes to recreate the desired functionality.
Architecture and Design · Operation · Sandbox or Jail
Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.
Architecture and Design · Attack Surface Reduction
For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
OWASP Cheat Sheets
Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
OS Command Injection Defense (opens in a new tab)
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V12.3.5 (opens in a new tab)
V5.3.8 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
Command Line Execution through SQL Injection (opens in a new tab)
Command Delimiters (opens in a new tab)
Exploiting Multiple Input Interpretation Layers (opens in a new tab)
Argument Injection (opens in a new tab)
OS Command Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 12 Feb 2026, 07:39 UTC

WeaknessesCWE-78

Technical details

References

Community reviews

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