{"id":"CVE-2026-21878","state":"PUBLISHED","title":"BACnet Stack Improperly Limits Pathnames to a Restricted Directory","description":"BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.5.0.rc3, a vulnerability has been discovered in BACnet Stack's file writing functionality where there is no validation of user-provided file paths, allowing attackers to write files to arbitrary directories. This affects apps/readfile/main.c and ports/posix/bacfile-posix.c. This vulnerability is fixed in 1.5.0.rc3.","publishedAt":"2026-02-13T18:10:26.325Z","updatedAt":"2026-02-13T18:53:59.648Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["bacnet-stack bacnet-stack"],"affected":[{"vendor":"bacnet-stack","product":"bacnet-stack","versions":[{"version":"< 1.5.0.rc3","status":"affected"}]}],"references":["https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-p8rx-c26w-545j","https://github.com/bacnet-stack/bacnet-stack/commit/c5dc00a77b4bc2550befa67a930b333e299c18f3"],"weaknesses":["CWE-22"],"ingestedAt":"2026-10-29T20:11:10.572Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/21xxx/CVE-2026-21878.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-21878","state":"PUBLISHED","datePublished":"2026-02-13T18:10:26.325Z","dateUpdated":"2026-02-13T18:53:59.648Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-01-05T17:24:36.928Z"},"containers":{"cna":{"title":"BACnet Stack Improperly Limits Pathnames to a Restricted Directory","descriptions":[{"lang":"en","value":"BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.5.0.rc3, a vulnerability has been discovered in BACnet Stack's file writing functionality where there is no validation of user-provided file paths, allowing attackers to write files to arbitrary directories. This affects apps/readfile/main.c and ports/posix/bacfile-posix.c. This vulnerability is fixed in 1.5.0.rc3."}],"affected":[{"vendor":"bacnet-stack","product":"bacnet-stack","versions":[{"version":"< 1.5.0.rc3","status":"affected"}]}],"references":[{"url":"https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-p8rx-c26w-545j","name":"https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-p8rx-c26w-545j","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/bacnet-stack/bacnet-stack/commit/c5dc00a77b4bc2550befa67a930b333e299c18f3","name":"https://github.com/bacnet-stack/bacnet-stack/commit/c5dc00a77b4bc2550befa67a930b333e299c18f3","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-22","lang":"en","description":"CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-02-13T18:10:26.325Z"},"source":{"advisory":"GHSA-p8rx-c26w-545j","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-02-13T18:53:41.608462Z","id":"CVE-2026-21878","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-02-13T18:53:59.648Z"}}]}}}