{"id":"CVE-2026-28207","state":"PUBLISHED","title":"Zen-C Vulnerable to Command Injection via Malicious Output Filename","description":"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.","publishedAt":"2026-02-26T22:17:58.898Z","updatedAt":"2026-03-02T20:48:09.055Z","severity":{"score":6.6,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["z-libs Zen-C"],"affected":[{"vendor":"z-libs","product":"Zen-C","versions":[{"version":"< 0.4.2","status":"affected"}]}],"references":["https://github.com/z-libs/Zen-C/security/advisories/GHSA-9rff-x96h-76h2","https://f0nduesav0yarde.github.io/blog/vulnerabilities/cve-2026-28207/"],"weaknesses":["CWE-78"],"ingestedAt":"2026-10-29T20:11:31.369Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/28xxx/CVE-2026-28207.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-28207","state":"PUBLISHED","datePublished":"2026-02-26T22:17:58.898Z","dateUpdated":"2026-03-02T20:48:09.055Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-02-25T15:28:40.648Z"},"containers":{"cna":{"title":"Zen-C Vulnerable to Command Injection via Malicious Output Filename","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."}],"affected":[{"vendor":"z-libs","product":"Zen-C","versions":[{"version":"< 0.4.2","status":"affected"}]}],"references":[{"url":"https://github.com/z-libs/Zen-C/security/advisories/GHSA-9rff-x96h-76h2","name":"https://github.com/z-libs/Zen-C/security/advisories/GHSA-9rff-x96h-76h2","tags":["x_refsource_CONFIRM"]}],"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","lang":"en","description":"CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-02-26T22:17:58.898Z"},"source":{"advisory":"GHSA-9rff-x96h-76h2","discovery":"UNKNOWN"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://f0nduesav0yarde.github.io/blog/vulnerabilities/cve-2026-28207/"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2026-02-27T16:57:44.054Z"},"x_generator":{"engine":"ADPogram 0.0.1"}},{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/z-libs/Zen-C/security/advisories/GHSA-9rff-x96h-76h2","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-02T20:48:05.636087Z","id":"CVE-2026-28207","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-02T20:48:09.055Z"}}]}}}