CVE-2026-28207 (GCVE-0-2026-28207)
Vulnerability from cvelistv5 – Published: 2026-02-26 22:17 – Updated: 2026-03-02 20:48
VLAI
EPSS
VEX
Title
Zen-C Vulnerable to Command Injection via Malicious Output Filename
Summary
Zen C is a systems programming language that compiles to human-readable GNU C/C11. Prior to version 0.4.2, a command injection vulnerability (CWE-78) in the Zen C compiler allows local attackers to execute arbitrary shell commands by providing a specially crafted output filename via the `-o` command-line argument. The vulnerability existed in the `main` application logic (specifically in `src/main.c`), where the compiler constructed a shell command string to invoke the backend C compiler. This command string was built by concatenating various arguments, including the user-controlled output filename, and was subsequently executed using the `system()` function. Because `system()` invokes a shell to parse and execute the command, shell metacharacters within the output filename were interpreted by the shell, leading to arbitrary command execution. An attacker who can influence the command-line arguments passed to the `zc` compiler (like through a build script or a CI/CD pipeline configuration) can execute arbitrary commands with the privileges of the user running the compiler. The vulnerability has been fixed in version 0.4.2 by removing `system()` calls, implementing `ArgList`, and internal argument handling. Users are advised to update to Zen C version v0.4.2 or later.
Severity
6.6 (Medium)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-03-02 20:48 UTC
CWE
- CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/z-libs/Zen-C/security/advisori… | x_refsource_CONFIRM |
| https://f0nduesav0yarde.github.io/blog/vulnerabil… |
Impacted products
{
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2026-02-27T16:57:44.054Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"url": "https://f0nduesav0yarde.github.io/blog/vulnerabilities/cve-2026-28207/"
}
],
"title": "CVE Program Container",
"x_generator": {
"engine": "ADPogram 0.0.1"
}
},
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-28207",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-02T20:48:05.636087Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-02T20:48:09.055Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"tags": [
"exploit"
],
"url": "https://github.com/z-libs/Zen-C/security/advisories/GHSA-9rff-x96h-76h2"
}
],
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "Zen-C",
"vendor": "z-libs",
"versions": [
{
"status": "affected",
"version": "\u003c 0.4.2"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Zen C is a systems programming language that compiles to human-readable GNU C/C11. Prior to version 0.4.2, a command injection vulnerability (CWE-78) in the Zen C compiler allows local attackers to execute arbitrary shell commands by providing a specially crafted output filename via the `-o` command-line argument. The vulnerability existed in the `main` application logic (specifically in `src/main.c`), where the compiler constructed a shell command string to invoke the backend C compiler. This command string was built by concatenating various arguments, including the user-controlled output filename, and was subsequently executed using the `system()` function. Because `system()` invokes a shell to parse and execute the command, shell metacharacters within the output filename were interpreted by the shell, leading to arbitrary command execution. An attacker who can influence the command-line arguments passed to the `zc` compiler (like through a build script or a CI/CD pipeline configuration) can execute arbitrary commands with the privileges of the user running the compiler. The vulnerability has been fixed in version 0.4.2 by removing `system()` calls, implementing `ArgList`, and internal argument handling. Users are advised to update to Zen C version v0.4.2 or later."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "LOW",
"baseScore": 6.6,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-78",
"description": "CWE-78: Improper Neutralization of Special Elements used in an OS Command (\u0027OS Command Injection\u0027)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-02-26T22:17:58.898Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/z-libs/Zen-C/security/advisories/GHSA-9rff-x96h-76h2",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/z-libs/Zen-C/security/advisories/GHSA-9rff-x96h-76h2"
}
],
"source": {
"advisory": "GHSA-9rff-x96h-76h2",
"discovery": "UNKNOWN"
},
"title": "Zen-C Vulnerable to Command Injection via Malicious Output Filename"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-28207",
"datePublished": "2026-02-26T22:17:58.898Z",
"dateReserved": "2026-02-25T15:28:40.648Z",
"dateUpdated": "2026-03-02T20:48:09.055Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-28207",
"date": "2026-11-08",
"epss": "0.0108",
"percentile": "0.65303"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"product": "Zen-C",
"vendor": "z-libs",
"versions": [
{
"status": "affected",
"version": "\u003c 0.4.2"
}
]
}
],
"source": "security-advisories@github.com"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:zenc-lang:zen_c:*:*:*:*:*:*:*:*",
"matchCriteriaId": "E084A39F-FF3F-487E-8E8A-F8F3C322A5AE",
"versionEndExcluding": "0.4.2",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Zen C is a systems programming language that compiles to human-readable GNU C/C11. Prior to version 0.4.2, a command injection vulnerability (CWE-78) in the Zen C compiler allows local attackers to execute arbitrary shell commands by providing a specially crafted output filename via the `-o` command-line argument. The vulnerability existed in the `main` application logic (specifically in `src/main.c`), where the compiler constructed a shell command string to invoke the backend C compiler. This command string was built by concatenating various arguments, including the user-controlled output filename, and was subsequently executed using the `system()` function. Because `system()` invokes a shell to parse and execute the command, shell metacharacters within the output filename were interpreted by the shell, leading to arbitrary command execution. An attacker who can influence the command-line arguments passed to the `zc` compiler (like through a build script or a CI/CD pipeline configuration) can execute arbitrary commands with the privileges of the user running the compiler. The vulnerability has been fixed in version 0.4.2 by removing `system()` calls, implementing `ArgList`, and internal argument handling. Users are advised to update to Zen C version v0.4.2 or later."
},
{
"lang": "es",
"value": "Zen C es un lenguaje de programaci\u00f3n de sistemas que compila a GNU C/C11 legible por humanos. Antes de la versi\u00f3n 0.4.2, una vulnerabilidad de inyecci\u00f3n de comandos (CWE-78) en el compilador Zen C permite a atacantes locales ejecutar comandos de shell arbitrarios proporcionando un nombre de archivo de salida especialmente dise\u00f1ado a trav\u00e9s del argumento de l\u00ednea de comandos \u0027-o\u0027. La vulnerabilidad exist\u00eda en la l\u00f3gica de la aplicaci\u00f3n \u0027main\u0027 (espec\u00edficamente en \u0027src/main.c\u0027), donde el compilador constru\u00eda una cadena de comandos de shell para invocar al compilador C de backend. Esta cadena de comandos se constru\u00eda concatenando varios argumentos, incluyendo el nombre de archivo de salida controlado por el usuario, y posteriormente se ejecutaba usando la funci\u00f3n \u0027system()\u0027. Debido a que \u0027system()\u0027 invoca un shell para analizar y ejecutar el comando, los metacaracteres de shell dentro del nombre de archivo de salida eran interpretados por el shell, lo que llevaba a la ejecuci\u00f3n arbitraria de comandos. Un atacante que puede influir en los argumentos de l\u00ednea de comandos pasados al compilador \u0027zc\u0027 (como a trav\u00e9s de un script de compilaci\u00f3n o una configuraci\u00f3n de pipeline de CI/CD) puede ejecutar comandos arbitrarios con los privilegios del usuario que ejecuta el compilador. La vulnerabilidad ha sido corregida en la versi\u00f3n 0.4.2 eliminando las llamadas a \u0027system()\u0027, implementando \u0027ArgList\u0027 y el manejo interno de argumentos. Se aconseja a los usuarios actualizar a la versi\u00f3n v0.4.2 de Zen C o posterior."
}
],
"id": "CVE-2026-28207",
"lastModified": "2026-06-17T10:28:19.953",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "LOW",
"baseScore": 6.6,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 4.7,
"source": "security-advisories@github.com",
"type": "Secondary"
},
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.3,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.3,
"impactScore": 5.9,
"source": "nvd@nist.gov",
"type": "Primary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-28207",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-02T20:48:05.636087Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-02-26T23:16:35.277",
"references": [
{
"source": "security-advisories@github.com",
"tags": [
"Exploit",
"Mitigation",
"Vendor Advisory"
],
"url": "https://github.com/z-libs/Zen-C/security/advisories/GHSA-9rff-x96h-76h2"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"tags": [
"Exploit",
"Third Party Advisory"
],
"url": "https://f0nduesav0yarde.github.io/blog/vulnerabilities/cve-2026-28207/"
},
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"tags": [
"Exploit",
"Mitigation",
"Vendor Advisory"
],
"url": "https://github.com/z-libs/Zen-C/security/advisories/GHSA-9rff-x96h-76h2"
}
],
"sourceIdentifier": "security-advisories@github.com",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-78"
}
],
"source": "security-advisories@github.com",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"current_release_date": "2026-03-27T07:51:33+00:00",
"cve": "CVE-2026-28207",
"id": "CVE-2026-28207",
"initial_release_date": "2026-01-01T00:00:00+00:00",
"product_status:known_not_affected": "1",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "Zen-C Vulnerable to Command Injection via Malicious Output Filename",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28207.json",
"version": "3"
},
"vulnrichment": {
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2026-02-27T16:57:44.054Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"url": "https://f0nduesav0yarde.github.io/blog/vulnerabilities/cve-2026-28207/"
}
],
"title": "CVE Program Container",
"x_generator": {
"engine": "ADPogram 0.0.1"
}
},
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-28207",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-02T20:48:05.636087Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-02T20:47:55.519Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"tags": [
"exploit"
],
"url": "https://github.com/z-libs/Zen-C/security/advisories/GHSA-9rff-x96h-76h2"
}
],
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "Zen-C",
"vendor": "z-libs",
"versions": [
{
"status": "affected",
"version": "\u003c 0.4.2"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Zen C is a systems programming language that compiles to human-readable GNU C/C11. Prior to version 0.4.2, a command injection vulnerability (CWE-78) in the Zen C compiler allows local attackers to execute arbitrary shell commands by providing a specially crafted output filename via the `-o` command-line argument. The vulnerability existed in the `main` application logic (specifically in `src/main.c`), where the compiler constructed a shell command string to invoke the backend C compiler. This command string was built by concatenating various arguments, including the user-controlled output filename, and was subsequently executed using the `system()` function. Because `system()` invokes a shell to parse and execute the command, shell metacharacters within the output filename were interpreted by the shell, leading to arbitrary command execution. An attacker who can influence the command-line arguments passed to the `zc` compiler (like through a build script or a CI/CD pipeline configuration) can execute arbitrary commands with the privileges of the user running the compiler. The vulnerability has been fixed in version 0.4.2 by removing `system()` calls, implementing `ArgList`, and internal argument handling. Users are advised to update to Zen C version v0.4.2 or later."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "LOW",
"baseScore": 6.6,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-78",
"description": "CWE-78: Improper Neutralization of Special Elements used in an OS Command (\u0027OS Command Injection\u0027)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-02-26T22:17:58.898Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/z-libs/Zen-C/security/advisories/GHSA-9rff-x96h-76h2",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/z-libs/Zen-C/security/advisories/GHSA-9rff-x96h-76h2"
}
],
"source": {
"advisory": "GHSA-9rff-x96h-76h2",
"discovery": "UNKNOWN"
},
"title": "Zen-C Vulnerable to Command Injection via Malicious Output Filename"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-28207",
"datePublished": "2026-02-26T22:17:58.898Z",
"dateReserved": "2026-02-25T15:28:40.648Z",
"dateUpdated": "2026-03-02T20:48:09.055Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
Loading timeline…
Loading…
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.