{"id":"CVE-2026-59730","aliases":["GHSA-r557-wffq-wvrc"],"url":"https://o3.security/vulnerability/CVE-2026-59730","summary":"@astrojs/node: Backslash-prefixed paths not recognized as internal by trailing-slash redirect","details":"### Impact\n\nWith `trailingSlash: 'always'` configured, the `@astrojs/node` standalone server's static file handler appends a trailing slash to request paths and issues a `301` redirect. Paths beginning with `/\\` (slash-backslash) were not recognized as internal paths, so the handler would echo the raw path back in the `Location` header. Because browsers treat `\\` as `/` per the WHATWG URL specification, the resulting redirect could resolve to an external host.\n\n**Preconditions:**\n- `trailingSlash: 'always'` must be set (non-default; the default is `'ignore'`)\n- The request path must not have a file extension in its final segment\n- An attacker must deliver the crafted link to a user\n\n### Patches\n\nFixed by treating backslash-prefixed paths the same as `//`-prefixed paths in `isInternalPath()`, so they are no longer rewritten with a trailing slash.\n\n### Workarounds\n\nUse the default `trailingSlash: 'ignore'` setting, which does not issue trailing-slash redirects in the static file handler.\n\n### References\n\n- [WHATWG URL spec: backslash normalization](https://url.spec.whatwg.org/#url-parsing)","published":"2026-07-27T20:00:28.662Z","modified":"2026-10-21T02:58:49.431661411Z","cvss":null,"epss":{"score":0.00359,"percentile":0.29242,"asOf":"2026-09-14"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@astrojs/node","fixedVersion":"11.0.2"}],"fix":{"url":"https://github.com/withastro/astro/commit/eb6f97e391ee587747e37609c255c7cd4b9cce3c","label":"withastro/astro@eb6f97e"},"references":[{"type":"WEB","url":"https://github.com/withastro/astro/releases/tag/@astrojs/node@11.0.2"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59730.json"},{"type":"ADVISORY","url":"https://github.com/withastro/astro/security/advisories/GHSA-r557-wffq-wvrc"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59730"},{"type":"FIX","url":"https://github.com/withastro/astro/commit/eb6f97e391ee587747e37609c255c7cd4b9cce3c"},{"type":"FIX","url":"https://github.com/withastro/astro/pull/17252"},{"type":"PACKAGE","url":"https://github.com/withastro/astro"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-21T02:58:49.431661411Z"}}