{"api_version":"1","generated_at":"2026-11-06T15:43:11+00:00","cve":"CVE-2026-87045","urls":{"html":"https://cve.report/CVE-2026-87045","api":"https://cve.report/api/cve/CVE-2026-87045.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-87045","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-87045"},"summary":{"title":"NULL pointer dereference in the Zephyr HTTP/2 server when a header block is completed by a CONTINUATION frame","description":"The HTTP/2 server in subsys/net/lib/http/http_server_http2.c clears the connection's stream binding at the start of every frame. handle_http_frame_header() executed client->current_stream = NULL unconditionally, but a CONTINUATION frame does not open a new stream and enter_http_frame_continuation_state() never re-bound one, so the rest of the header block was processed with client->current_stream unset. Two paths then write through the NULL pointer. A request for an unregistered resource, or a method the matched resource does not support, is answered by send_http2_404() or send_http2_405(), and both call send_headers_frame(), which unconditionally sets client->current_stream->headers_sent = true. A POST, PUT or PATCH to a registered dynamic resource reaches handle_http2_dynamic_resource(), which unlike its siblings (handle_http2_static_resource(), dynamic_get_del_opts_req_v2(), dynamic_post_put_req_v2()) had no client->current_stream == NULL guard, and stores through the pointer with client->current_stream->current_detail = dynamic_detail.\n\nAny peer that can reach the server can trigger this without authentication or prior state. A single stray CONTINUATION frame with END_HEADERS set, sent right after the client preface and requesting any unregistered path, is enough, because nothing rejected a CONTINUATION that no HEADERS frame had opened. A legitimate split header block (a HEADERS frame with END_HEADERS clear whose payload ends on a header-field boundary, then a CONTINUATION with END_HEADERS set) reaches the same state. The in-tree test test_http2_post_headers_with_continuation() did not catch this because it splits the header block mid field, which takes the handle_incomplete_http_header() shortcut that keeps the stream bound.\n\nThe result is a write to a fixed low address (a small offset into struct http2_stream_ctx), which faults on mainstream targets (flash/vector-table region on Cortex-M, or a trap under MPU/MMU null-pointer detection), and the default fatal-error handler halts the system. Impact is an unauthenticated, remotely triggerable denial of service against any device running the HTTP/2 server: the 404 path needs no particular resource to be registered, and HTTP/2 is built into CONFIG_HTTP_SERVER with cleartext h2c accepted, so TLS does not prevent it. Neither the target address nor the written value is attacker-controlled, so there is no confidentiality or integrity impact. Applications built without CONFIG_HTTP_SERVER are not affected.","state":"PUBLISHED","assigner":"zephyr","published_at":"2026-11-06 15:17:26","updated_at":"2026-11-06 15:17:27"},"problem_types":["CWE-476","CWE-476 memory-safety"],"metrics":[{"version":"3.1","source":"vulnerabilities@zephyrproject.org","type":"Secondary","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"CVSS","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/e72a9d9498092bfbb7feed4b479bf21bc3218c3d","name":"https://github.com/zephyrproject-rtos/zephyr/commit/e72a9d9498092bfbb7feed4b479bf21bc3218c3d","refsource":"vulnerabilities@zephyrproject.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-cw8r-2jj2-w8fw","name":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-cw8r-2jj2-w8fw","refsource":"vulnerabilities@zephyrproject.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-87045","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-87045","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"zephyrproject","product":"zephyr","version":"affected 4.1.0 4.3.2 semver","platforms":[]},{"source":"CNA","vendor":"zephyrproject","product":"zephyr","version":"affected 4.4.0 4.5.0 semver","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"collectionURL":"https://github.com/zephyrproject-rtos/zephyr","defaultStatus":"unaffected","packageName":"zephyr","product":"zephyr","programFiles":["subsys/net/lib/http/http_server_http2.c"],"programRoutines":[{"name":"enter_http_frame_continuation_state"},{"name":"handle_http2_dynamic_resource"},{"name":"handle_http_frame_header"},{"name":"handle_http_frame_headers"},{"name":"send_headers_frame"}],"vendor":"zephyrproject","versions":[{"lessThan":"4.3.2","status":"affected","version":"4.1.0","versionType":"semver"},{"lessThan":"4.5.0","status":"affected","version":"4.4.0","versionType":"semver"}]}],"descriptions":[{"lang":"en","value":"The HTTP/2 server in subsys/net/lib/http/http_server_http2.c clears the connection's stream binding at the start of every frame. handle_http_frame_header() executed client->current_stream = NULL unconditionally, but a CONTINUATION frame does not open a new stream and enter_http_frame_continuation_state() never re-bound one, so the rest of the header block was processed with client->current_stream unset. Two paths then write through the NULL pointer. A request for an unregistered resource, or a method the matched resource does not support, is answered by send_http2_404() or send_http2_405(), and both call send_headers_frame(), which unconditionally sets client->current_stream->headers_sent = true. A POST, PUT or PATCH to a registered dynamic resource reaches handle_http2_dynamic_resource(), which unlike its siblings (handle_http2_static_resource(), dynamic_get_del_opts_req_v2(), dynamic_post_put_req_v2()) had no client->current_stream == NULL guard, and stores through the pointer with client->current_stream->current_detail = dynamic_detail.\n\nAny peer that can reach the server can trigger this without authentication or prior state. A single stray CONTINUATION frame with END_HEADERS set, sent right after the client preface and requesting any unregistered path, is enough, because nothing rejected a CONTINUATION that no HEADERS frame had opened. A legitimate split header block (a HEADERS frame with END_HEADERS clear whose payload ends on a header-field boundary, then a CONTINUATION with END_HEADERS set) reaches the same state. The in-tree test test_http2_post_headers_with_continuation() did not catch this because it splits the header block mid field, which takes the handle_incomplete_http_header() shortcut that keeps the stream bound.\n\nThe result is a write to a fixed low address (a small offset into struct http2_stream_ctx), which faults on mainstream targets (flash/vector-table region on Cortex-M, or a trap under MPU/MMU null-pointer detection), and the default fatal-error handler halts the system. Impact is an unauthenticated, remotely triggerable denial of service against any device running the HTTP/2 server: the 404 path needs no particular resource to be registered, and HTTP/2 is built into CONFIG_HTTP_SERVER with cleartext h2c accepted, so TLS does not prevent it. Neither the target address nor the written value is attacker-controlled, so there is no confidentiality or integrity impact. Applications built without CONFIG_HTTP_SERVER are not affected."}],"metrics":[{"cvssV3_1":{"baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-476","description":"memory-safety","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-11-06T14:38:25.629Z","orgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","shortName":"zephyr"},"references":[{"name":"Fix commit","tags":["patch"],"url":"https://github.com/zephyrproject-rtos/zephyr/commit/e72a9d9498092bfbb7feed4b479bf21bc3218c3d"},{"name":"GHSA-cw8r-2jj2-w8fw","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-cw8r-2jj2-w8fw"}],"title":"NULL pointer dereference in the Zephyr HTTP/2 server when a header block is completed by a CONTINUATION frame","x_generator":{"engine":"cvelib 1.8.0"}}},"cveMetadata":{"assignerOrgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","assignerShortName":"zephyr","cveId":"CVE-2026-87045","datePublished":"2026-11-06T14:38:25.629Z","dateReserved":"2026-09-08T18:40:52.193Z","dateUpdated":"2026-11-06T14:38:25.629Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-11-06 15:17:26","lastModifiedDate":"2026-11-06 15:17:27","problem_types":["CWE-476","CWE-476 memory-safety"],"metrics":{"cvssMetricV31":[{"source":"vulnerabilities@zephyrproject.org","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"87045","Ordinal":"1","Title":"NULL pointer dereference in the Zephyr HTTP/2 server when a head","CVE":"CVE-2026-87045","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"87045","Ordinal":"1","NoteData":"The HTTP/2 server in subsys/net/lib/http/http_server_http2.c clears the connection's stream binding at the start of every frame. handle_http_frame_header() executed client->current_stream = NULL unconditionally, but a CONTINUATION frame does not open a new stream and enter_http_frame_continuation_state() never re-bound one, so the rest of the header block was processed with client->current_stream unset. Two paths then write through the NULL pointer. A request for an unregistered resource, or a method the matched resource does not support, is answered by send_http2_404() or send_http2_405(), and both call send_headers_frame(), which unconditionally sets client->current_stream->headers_sent = true. A POST, PUT or PATCH to a registered dynamic resource reaches handle_http2_dynamic_resource(), which unlike its siblings (handle_http2_static_resource(), dynamic_get_del_opts_req_v2(), dynamic_post_put_req_v2()) had no client->current_stream == NULL guard, and stores through the pointer with client->current_stream->current_detail = dynamic_detail.\n\nAny peer that can reach the server can trigger this without authentication or prior state. A single stray CONTINUATION frame with END_HEADERS set, sent right after the client preface and requesting any unregistered path, is enough, because nothing rejected a CONTINUATION that no HEADERS frame had opened. A legitimate split header block (a HEADERS frame with END_HEADERS clear whose payload ends on a header-field boundary, then a CONTINUATION with END_HEADERS set) reaches the same state. The in-tree test test_http2_post_headers_with_continuation() did not catch this because it splits the header block mid field, which takes the handle_incomplete_http_header() shortcut that keeps the stream bound.\n\nThe result is a write to a fixed low address (a small offset into struct http2_stream_ctx), which faults on mainstream targets (flash/vector-table region on Cortex-M, or a trap under MPU/MMU null-pointer detection), and the default fatal-error handler halts the system. Impact is an unauthenticated, remotely triggerable denial of service against any device running the HTTP/2 server: the 404 path needs no particular resource to be registered, and HTTP/2 is built into CONFIG_HTTP_SERVER with cleartext h2c accepted, so TLS does not prevent it. Neither the target address nor the written value is attacker-controlled, so there is no confidentiality or integrity impact. Applications built without CONFIG_HTTP_SERVER are not affected.","Type":"Description","Title":"NULL pointer dereference in the Zephyr HTTP/2 server when a head"}]}}}