{"items":[{"id":"NVI-00016176","kind":"vulnerability","title":"Astro: XSS via Unescaped Attribute Names in Spread Props","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-jrpj-wcv7-9fh9","CVE-2026-54298"],"plain_summary":"GitHub lists this reviewed advisory for astro. 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-3b3e27b2b3db16ed8193c283cac6e416"],"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":"2026-07-18T17:25:06.000Z","value":"4.2 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-3b3e27b2b3db16ed8193c283cac6e416"}],"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-3b3e27b2b3db16ed8193c283cac6e416","url":"https://github.com/advisories/GHSA-jrpj-wcv7-9fh9","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-jrpj-wcv7-9fh9","publisher":"GitHub Advisory Database","observed_at":"2026-11-04T02:49:06.528Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-3b3e27b2b3db16ed8193c283cac6e416"],"technology":"astro","known_exclusions":[],"conditions_summary":"## Summary\n\nThe `spreadAttributes` function in Astro's server-side rendering pipeline iterates over object keys and passes them directly to `addAttribute`, which interpolates the key into the HTML output without escaping. When a developer uses the spread syntax `{...props}` on an HTML element and the object keys come from an untrusted source (API, CMS, URL parameters), an attacker can inject arbitrary HTML attributes including event handlers like `onmousemove`, `onclick`, or break out of the attribute context entirely to inject new elements.\n\n## Details\n\nThe vulnerable function is `addAttribute` at `packages/astro/src/runtime/server/render/util.ts:81-141`:\n\n```javascript\nexport function addAttribute(value: any, key: string, shouldEscape = true, tagName = '') {\n    if (value == null) {\n        return '';\n    }\n    \n    return markHTMLString(` ${key}=\"${toAttributeString(value, shouldEscape)}\"`); //  key interpolated not escaped\n}\n```\n\nThis function is called from `spreadAttributes`","public_affected_ranges":["< 6.4.6"]}],"null_published_at":"2026-11-04T10:04:27.902Z","source_updated_at":"2026-07-18T17:25:06.000Z","source_disclosed_at":"2026-06-16T14:57:21.000Z","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":"2026-11-04T02:49:06.528Z"}],"next_cursor":null,"snapshot_revision":"42594"}