Is CVE-2026-59355 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-59355 being exploited in the wild.

How severe is CVE-2026-59355?

Medium severity, with a CVSS score of 6.1, published 27 August 2026.

Which products and versions are affected?

Spring Authorization Server 1.5.0 through 1.5.7.

Is there a fix for CVE-2026-59355?

A patch was published on 2026-06-09: version 1.5.8 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-59355 attacked?

It is attacked over the network.

Am I affected by CVE-2026-59355?

Check whether you run Spring Authorization Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-59355: Spring Authorization Server open redirect via request_uri parameter

CVE-2026-59355 · Severity: medium · CVSS 6.1 · Published 2026-08-27

Spring Authorization Server, a framework component used to implement OAuth 2.0 and OpenID Connect authentication in Java applications, contains an insufficient validation flaw in its authorization endpoint. An attacker can craft a malicious request with an invalid request_uri parameter paired with an unvalidated redirect_uri to redirect authenticated users to attacker-controlled sites, potentially enabling phishing, credential theft, or malware distribution.

Technologies: Spring Authorization Server. Vendors: Spring.

Quick answers

Is CVE-2026-59355 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-59355 being exploited in the wild.
How severe is CVE-2026-59355?: Medium severity, with a CVSS score of 6.1, published 27 August 2026.
Which products and versions are affected?: Spring Authorization Server 1.5.0 through 1.5.7.
Is there a fix for CVE-2026-59355?: A patch was published on 2026-06-09: version 1.5.8 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-59355 attacked?: It is attacked over the network.
Am I affected by CVE-2026-59355?: Check whether you run Spring Authorization Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is an open redirect flaw in Spring Authorization Server versions 1.5.0 through 1.5.7 in the authorization endpoint's handling of the request_uri parameter. The authorization endpoint performs insufficient validation when processing authorization requests with invalid request_uri values paired with unvalidated redirect_uri parameters, allowing an attacker to specify a redirect destination outside the intended application. This is a server-side open redirect vulnerability that can be exploited via a crafted HTTP request to the authorization endpoint; no authentication or user interaction (beyond the OAuth flow itself) is required. An attacker can use this to redirect users to arbitrary external sites during the OAuth authentication flow. Patches are available in versions 1.5.8 and later.

Affected products

Spring Authorization Server 1.5.0 through 1.5.7

Timeline

2026-08-27: disclosed
2026-06-09: patched: version 1.5.8 released

References

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