{"items":[{"id":"NVI-00016350","kind":"vulnerability","title":"Netty: Security Control Bypass via CORS Short-Circuit Failure","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-6cqp-g7gg-8hr5","CVE-2026-56746"],"plain_summary":"GitHub lists this reviewed advisory for io.netty:netty-codec-http, io.netty:netty-codec-http. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-6a2c67e6f275ffbc17f5be7182c493a2"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-07-22T21:42:19.000Z","value":"6.5 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-6a2c67e6f275ffbc17f5be7182c493a2"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-6a2c67e6f275ffbc17f5be7182c493a2","url":"https://github.com/advisories/GHSA-6cqp-g7gg-8hr5","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-6cqp-g7gg-8hr5","publisher":"GitHub Advisory Database","observed_at":"2026-11-03T22:34:39.734Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-6a2c67e6f275ffbc17f5be7182c493a2"],"technology":"io.netty:netty-codec-http","known_exclusions":[],"conditions_summary":"### Summary\nNetty's CorsHandler provides a `shortCircuit()` configuration designed to reject unauthorized cross-origin requests immediately, acting as a security control before requests reach the application. However, due to a logical operator error in the origin evaluation process, this protection can be entirely bypassed. An attacker can bypass the short-circuit mechanism by sending a request with an `Origin: null` header. This failure forwards unauthorized requests to the backend application, bypassing intended access controls.\n\n### Details\nIn `io.netty.handler.codec.http.cors.CorsHandler#channelRead`, the short-circuit logic relies on the configuration returned by `getForOrigin(origin)` to determine if an origin is authorized. If `getForOrigin` returns a configuration object, the short-circuit check `(!(origin == null || config != null))` is bypassed, and the request proceeds to the backend.\n\nThe vulnerability is located in the `getForOrigin` method:\n\n```java\n            if (corsConfig.isNullOriginAllowed() || NULL_ORIGIN.equals(requestOrigin)) {\n                return corsConfig;\n            }\n```\n\nIf an attacker sends `Origin: null`, `NULL_ORIGIN.equals(requestOrigin)` evalua","public_affected_ranges":[">= 4.2.0.Final, < 4.2.16.Final"]},{"certainty":"source_listed","source_ids":["sr-6a2c67e6f275ffbc17f5be7182c493a2"],"technology":"io.netty:netty-codec-http","known_exclusions":[],"conditions_summary":"### Summary\nNetty's CorsHandler provides a `shortCircuit()` configuration designed to reject unauthorized cross-origin requests immediately, acting as a security control before requests reach the application. However, due to a logical operator error in the origin evaluation process, this protection can be entirely bypassed. An attacker can bypass the short-circuit mechanism by sending a request with an `Origin: null` header. This failure forwards unauthorized requests to the backend application, bypassing intended access controls.\n\n### Details\nIn `io.netty.handler.codec.http.cors.CorsHandler#channelRead`, the short-circuit logic relies on the configuration returned by `getForOrigin(origin)` to determine if an origin is authorized. If `getForOrigin` returns a configuration object, the short-circuit check `(!(origin == null || config != null))` is bypassed, and the request proceeds to the backend.\n\nThe vulnerability is located in the `getForOrigin` method:\n\n```java\n            if (corsConfig.isNullOriginAllowed() || NULL_ORIGIN.equals(requestOrigin)) {\n                return corsConfig;\n            }\n```\n\nIf an attacker sends `Origin: null`, `NULL_ORIGIN.equals(requestOrigin)` evalua","public_affected_ranges":["< 4.1.136.Final"]}],"null_published_at":"2026-11-04T10:04:27.935Z","source_updated_at":"2026-07-22T21:42:19.000Z","source_disclosed_at":"2026-07-22T21:42:17.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-03T22:34:39.734Z"}],"next_cursor":null,"snapshot_revision":"42594"}