Victim-session data access via OIDC redirect state
Published Aug 18, 2026 · Updated Aug 20, 2026
Improper access control in OIDC handling in Oracle Helidon 4.5.0 allows remote attackers to read or modify application data via crafted login flows. Public fix notes show that the OIDC provider accepted legacy raw local redirect URIs in the state parameter and could hand off raw access tokens in callback query parameters instead of binding short-lived encrypted values to the login flow. Exploitation requires user interaction with an attacker-controlled login or callback URL and is bounded to actions that the victim's authenticated session can perform.
Summary
What happened
Improper access control in OIDC handling in Oracle Helidon 4.5.0 allows remote attackers to read or modify application data via crafted login flows. Public fix notes show that the OIDC provider accepted legacy raw local redirect URIs in the state parameter and could hand off raw access tokens in callback query parameters instead of binding short-lived encrypted values to the login flow. Exploitation requires user interaction with an attacker-controlled login or callback URL and is bounded to actions that the victim's authenticated session can perform.
The record
- CVE
- CVE-2026-73870
- Published
- Aug 18, 2026
- Updated
- Aug 20, 2026
- Vendor
- Oracle
- Product
- Helidon
- Classifications
- CWE-284
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 18, 2026CVE publishedPublication date reported by the CVE source.
- Aug 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=4.5.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Technologies
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