What’s Vulnerable › Vulnerabilities

CVE-2026-103030: Dio: Cross-origin redirect leaks sensitive request headers in `dio_http2_adapter`

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-13 · updated 2026-10-16
• Weakness: CWE-200

Description

Dio is a powerful HTTP client for Dart and Flutter. From 1.0.0 until 2.8.0, dio_http2_adapter follows redirects in Http2Adapter._fetch by copying the original RequestOptions.headers into the redirected HTTP/2 request without comparing the source and destination origins. A server contacted by an application can return a cross-origin Location redirect to a different-origin destination, which then receives preserved Authorization, Cookie, and Proxy-Authorization headers because RequestOptions.copyWith retains the full header map. The issue applies when applications use Http2Adapter for authenticated requests, and redirect following is enabled by default. This issue is fixed in version 2.8.0.

Affected products

• cfug dio: from 1.0.0, < 2.8.0

References

• https://github.com/cfug/dio/commit/9d7ac913340084f3b4987b121e076f28d637a81e
• https://github.com/cfug/dio/releases/tag/http2_adapter_v2.8.0
• https://github.com/cfug/dio/security/advisories/GHSA-cr65-55v9-xhvv
• https://github.com/cfug/dio/security/advisories/GHSA-cr65-55v9-xhvv

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