{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-5067: Out-of-bounds read/write in HTTP WebSocket upgrade via non-null-terminated Sec-WebSocket-Key","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-5067","status":"final","version":"1","initial_release_date":"2026-06-09T06:01:02.559Z","current_release_date":"2026-06-09T13:12:08.853Z","revision_history":[{"date":"2026-06-09T06:01:02.559Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"A remote, unauthenticated attacker can trigger memory corruption in Zephyr's HTTP server WebSocket upgrade path by sending a crafted Sec-WebSocket-Key header. The HTTP/1 header parser copies the header into a fixed-size buffer using a bounded copy that does not guarantee NUL termination when the input length reaches the buffer size. During upgrade handling the buffer is copied to a local stack buffer and passed to strlen(); if no NUL exists in-bounds, strlen() reads beyond the stack buffer and subsequent concatenation with the WebSocket magic string can write out of bounds. This leads to out-of-bounds read and write on stack memory, resulting in crash (denial of service) and potentially code execution. The path is reachable when CONFIG_HTTP_SERVER_WEBSOCKET is enabled.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-5067 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-5067"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-5067"},{"category":"external","summary":"github.com","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wgr4-9pwq-94vj"}]},"product_tree":{"branches":[{"category":"vendor","name":"zephyrproject-rtos","branches":[{"category":"product_name","name":"Zephyr","branches":[{"category":"product_version_range","name":">=3.7.0 <=4.3.0","product":{"name":"zephyrproject-rtos Zephyr >=3.7.0 <=4.3.0","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:zephyrproject-rtos:zephyr:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-5067","title":"Out-of-bounds read/write in HTTP WebSocket upgrade via non-null-terminated Sec-WebSocket-Key","notes":[{"category":"description","text":"A remote, unauthenticated attacker can trigger memory corruption in Zephyr's HTTP server WebSocket upgrade path by sending a crafted Sec-WebSocket-Key header. The HTTP/1 header parser copies the header into a fixed-size buffer using a bounded copy that does not guarantee NUL termination when the input length reaches the buffer size. During upgrade handling the buffer is copied to a local stack buffer and passed to strlen(); if no NUL exists in-bounds, strlen() reads beyond the stack buffer and subsequent concatenation with the WebSocket magic string can write out of bounds. This leads to out-of-bounds read and write on stack memory, resulting in crash (denial of service) and potentially code execution. The path is reachable when CONFIG_HTTP_SERVER_WEBSOCKET is enabled.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1"]},"scores":[{"cvss_v3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"products":["CSAFPID-1"]}],"remediations":[{"category":"none_available","details":"No fixed version is published yet. Monitor the upstream advisory.","product_ids":["CSAFPID-1"]}]}]}