ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2026-103030

Dio: Cross-origin redirect leaks sensitive request headers in

Published Oct 13, 2026 · catalog updated Oct 15, 2026 · Dio: Cross-origin redirect leaks

Check if you run it

No confirmed exploitation is on record for CVE-2026-103030. EPSS is 0.36%. Act only if a listed version of Dio: Cross-origin redirect leaks is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Dio: Cross-origin redirect leaks).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.36%
Remediation
Version ranges on file
Affected products
Pub dio_http2_adapter · pub dio_http2_adapter · vendor cfug dio

### Summary follows HTTP 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 redirect receives the victim's , , and headers verbatim. This vulnerability has a CVSS v3.1 base score of **7.5 (High)** because is enabled by default, no authentication is required to exploit it, and the confidentiality impact is high. ### Details When is configured to use , the adapter's internal method constructs HTTP/2 request headers by unconditionally copying all entries from : On receiving a response, the adapter reads the header and resolves the redirect target URI: is called without an explicit argument; therefore preserves the full original header map via . ( ) returns an attacker-controlled cross-origin URI without any origin comparison. The combination means that on every redirect, the full set of original sensitive headers — including , , and — is forwarded to the new authority with no sanitization. **Data flow (source → sink):** 1. — public entry point. 2. — base and per-request headers merged into . 3. — dispatches to . 4. — header is read from the network response (attacker-controlled source). 5. — redirect target URI resolved; cross-origin check absent. 6. — called without override. 7. — preserves — all sensitive headers retained. 8. — preserved headers emitted verbatim to the cross-origin HTTP/2 request (sink). **Suggested patch** — strip sensitive headers before following a cross-origin redirect: ### PoC The following steps reproduce the vulnerability using two local HTTP/2 cleartext (h2c) servers inside an isolated Docker container (no external network required). **Prerequisites:** - Docker installed and accessible. - Repository checked out at the path used as the build context. **Build and run:** **What the container does:** 1. Starts an *origin* h2c server on that immediately returns . 2. Starts an *attacker* h2c server on that logs every received head

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Pub dio_http2_adapter1.0.0 → 2.8.0
  • pub dio_http2_adapter>= 1.0.0, <= 2.7.1
  • vendor cfug dioversion unspecified

How to fix CVE-2026-103030

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-103030. EPSS is 0.36%. Act only if a listed version of Dio: Cross-origin redirect leaks is installed.

Which versions are affected?

Compare what you have installed with 1.0.0 → 2.8.0, >= 1.0.0, <= 2.7.1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-200: Exposure of Sensitive Information. EPSS 0.36%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 15, 2026 · GitHub Advisory Database

    Detected

    ### Summary follows HTTP 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 redirect receives the victim's , , and headers verbatim. This vulnerability has a CVSS v3.1 base score of **7.5 (High)** because is enabled by default, no authentication is required to exploit it, and the

  2. Oct 15, 2026 · GitHub Advisory Database

    Fix available

    dio_http2_adapter fixed in 2.8.0

  3. Oct 15, 2026 · GitHub Advisory Database

    Fix available

    dio_http2_adapter fixed in 2.8.0

  4. Oct 15, 2026 · GitHub Advisory Database

    Updated

    ### Summary follows HTTP 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 redirect receives the victim's , , and headers verbatim. This vulnerability has a CVSS v3.1 base score of **7.5 (High)** because is enabled by default, no authentication is required to exploit it, and the

Sources

  • CVE.orgVulnerability recordCVE-2026-103030

    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

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-103030

    30-day exploitation probability 0.4%

    first.org
  • GitHub Advisory DatabasePackage advisoryGHSA-cr65-55v9-xhvv

    GitHub Advisory Database record mirrored by OSV.

    github.com
  • OpenSSF OSV / OSV ScannerPackage advisoryGHSA-cr65-55v9-xhvv

    Dio: Cross-origin redirect leaks sensitive request headers in

    osv.dev

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.