Information Disclosure in dio_http2_adapter (CVE-2026-103030)
Summary
Vulnerability in dio_http2_adapter (CVE-2026-103030). Confidential information can be exposed externally. Exploitable via Authorization header. Mitigation: upgrade to 2.8.0 or later.
Original description
The description as published by the source.
Summary
dio_http2_adapter follows HTTP Location redirects without stripping sensitive request headers when the redirect target is a different origin. An attacker who can cause any origin server to return a cross-origin 302 redirect receives the victim's Authorization, Cookie, and Proxy-Authorization headers verbatim. This vulnerability has a CVSS v3.1 base score of 7.5 (High) because followRedirects is enabled by default, no authentication is required to exploit it, and the confidentiality impact is high.
Details
When Dio is configured to use Http2Adapter, the adapter's internal _fetch method constructs HTTP/2 request headers by unconditionally copying all entries from options.headers:
// plugins/http2_adapter/lib/src/http2_adapter.dart:111
headers.addAll(
options.headers.entries.map((entry) {
...
return Header.ascii(entry.key.toLowerCase(), v);
}).toList(),
);
On receiving a 3xx response, the adapter reads the Location header and resolves the redirect target URI:
// plugins/http2_adapter/lib/src/http2_adapter.dart:254-263
final url = responseHeaders.value('location');
final uri = Uri.parse(url ?? '');
final String path = resolveRedirectUri(options.uri, uri).toString();
return _fetch(options.copyWith(path: path, maxRedirects: --options.maxRedirects), ...);
options.copyWith is called without an explicit headers argument; dio/lib/src/options.dart:629 therefore preserves the full original head…
Source: NIST National Vulnerability Database 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-2026-103030 has been found in dio_http2_adapter.
Attackers can target a specific entry point like Authorization header over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: upgrade dio_http2_adapter to 2.8.0 or later.
If unsure, ask your IT team or search "dio_http2_adapter CVE-2026-103030" on the vendor's site.
CVE-2026-103030 (dio_http2_adapter) — CWE-200 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: Authorization header / Cookie header / dio_http2_adapter / Location
Patched: 2.8.0 — apply immediately
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.
Information disclosure (CWE-200) exists in dio_http2_adapter. Attackers reach the vulnerable code path via Authorization header without authentication.
Check the vendor advisory for the affected versions of dio_http2_adapter. Attack surface: Authorization header / Cookie header / dio_http2_adapter / Location.
Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.
Update to 2.8.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'dio_http2_adapter' . 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 'dio_http2_adapter' . | 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
dio_http2_adapterを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade dio_http2_adapter to 2.8.0ステージング環境で 2.8.0 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。
-
3Post-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 nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com