Cross-Site Scripting (XSS) in astro (CVE-2026-59727)
Summary
Cross-site scripting in astro (CVE-2026-59727). Risk of unauthorized operations or information disclosure. Exploitable via attrs. Mitigation: upgrade to 7.0.4 or later.
Original description
The description as published by the source.
Astro is a web framework for content-driven websites. In versions 3.10.0 through 7.0.3, when a transition:persist, transition:scope, or transition:persist-props directive is applied to a client-hydrated (client:*) component, Astro copied the directive value onto the rendered element without HTML-escaping it. If a developer reflects attacker-controlled input into one of these directives, an attacker can break out of the attribute and inject arbitrary HTML/JavaScript into the server-rendered output, resulting in reflected cross-site scripting (XSS). Exploitation requires the application developer to have written a non-idiomatic pattern — passing untrusted, request-derived input directly into a transition directive. Astro applications that do not route untrusted input into these directives are unaffected. This issue has been fixed in version 7.0.4.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-59727 has been found in astro.
Attackers can target a specific entry point like attrs over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade astro to 7.0.4 or later.
If unsure, ask your IT team or search "astro CVE-2026-59727" on the vendor's site.
CVE-2026-59727 (astro) — CWE-79
Attack surface: attrs / props / opts
Patched: 7.0.4 — apply immediately
Workaround: Do not pass untrusted or request-derived input into transition:persist, transition:scope, or transition:persist-props.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in astro. Attackers reach the vulnerable code path via attrs.
Check the vendor advisory for the affected versions of astro. Attack surface: attrs / props / opts.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 7.0.4.
Workaround: Do not pass untrusted or request-derived input into transition:persist, transition:scope, or transition:persist-props.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'astro' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'astro' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
astroを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
Do not pass untrusted or request-derived input into `transition:persist`, `transition:scope`, or `transition:persist-props`.パッチが適用されるまでの応急処置として、Do not pass untrusted or request-derived input into
transition:persist,transition:scope, ortransition:persist-props. を実施。回避策の副作用 (機能低下) を確認した上で。 -
3Apply patch patch
Upgrade astro to 7.0.4ステージング環境で 7.0.4 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- patch github.com
- patch github.com
- web github.com
- web github.com