{"id":"CVE-2026-88899","summary":"knowns before 0.31.0 External Control of Agent Working Directory via x-opencode-directory Header","details":"knowns versions before 0.31.0 fail to properly validate the x-opencode-directory request header in the /api/opencode proxy endpoint. Remote attackers can supply arbitrary directory paths to execute file operations outside the project root on the host system.","aliases":["GHSA-9h2q-r9fh-f98w"],"modified":"2026-09-12T11:31:00.061074404Z","published":"2026-09-10T15:28:51.729Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/88xxx/CVE-2026-88899.json","cna_assigner":"VulnCheck","cwe_ids":["CWE-73"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/88xxx/CVE-2026-88899.json"},{"type":"ADVISORY","url":"https://github.com/knowns-dev/knowns/releases/tag/v0.31.0"},{"type":"ADVISORY","url":"https://github.com/knowns-dev/knowns/security/advisories/GHSA-9h2q-r9fh-f98w"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-88899"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/knowns-before-0.31.0-external-control-of-agent-working-directory-via-x-opencode-directory-header"},{"type":"FIX","url":"https://github.com/knowns-dev/knowns/commit/37db0561b37b48b8bd035a417d7f1da6258ae657"},{"type":"ARTICLE","url":"https://github.com/knowns-dev/knowns/blob/v0.30.0/internal/server/server.go#L1283-L1296"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/knowns-dev/knowns","events":[{"introduced":"0"},{"fixed":"193ab83f6dbe1a6d4a0cf63283c57d6a93bea9ef"},{"fixed":"37db0561b37b48b8bd035a417d7f1da6258ae657"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"0.31.0"}],"source":["DESCRIPTION","REFERENCES"]}}],"versions":["v0.30.0","v0.29.1","v0.29.0","v0.28.0","v0.27.1","v0.27.0","v0.23.0","v0.26.0","v0.25.0","v0.24.1","v0.24.0","v0.22.2","v0.22.1","v0.22.0","v0.21.0","v0.20.5","v0.20.4","v0.20.3","v0.20.2","v0.20.1","v0.20.0","v0.19.2","v0.19.1","v0.19.0","v0.18.4","v0.18.3","v0.18.2","v0.18.1","v0.18.0","v0.17.1","v0.17.0","v0.16.3","v0.16.2","v0.16.1","v0.16.0","v0.15.3","v0.15.2","v0.15.1","v0.15.0","v0.12.4","v0.12.3","v0.12.2","v0.12.1","v0.12.0","v0.11.4","v0.11.3","v0.11.2","v0.11.1","v0.11.0","v0.10.6","v0.10.5","v0.10.4","v0.10.3","v0.10.2","v0.10.1","v0.10.0","v0.9.0","v0.8.9","v0.8.8","v0.8.7","v0.8.6","v0.8.5","v0.8.4","v0.8.3","v0.8.2","v0.8.1","v0.8.0","v0.7.0","v0.6.0","v0.5.0","v0.4.0","v0.3.1","v0.3.0","v0.2.1","v0.2.0","v0.1.8","v0.1.7","v0.1.6","v0.1.5","v0.1.4","v0.1.3","v0.1.2","v0.1.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-88899.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}