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OpenAdvisories
Medium · 6.5 CVE-2026-32245 EUVD-2026-11679GHSA-xg2q-62g2-cvcmGO-2026-4689

Tinyauth's OIDC authorization codes are not bound to client on token exchange

Published Mar 12, 2026 · Updated Mar 12, 2026 · Assigned by GitHub_M

Description

Tinyauth is an authentication and authorization server. Prior to 5.0.3, the OIDC token endpoint does not verify that the client exchanging an authorization code is the same client the code was issued to. A malicious OIDC client operator can exchange another client's authorization code using their own client credentials, obtaining tokens for users who never authorized their application. This violates RFC 6749 Section 4.1.3. This vulnerability is fixed in 5.0.3.

Affected products

VendorProductAffectedFixed
steveiliop56 tinyauth < 5.0.3 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1
openSUSE Leap 15.6 govulncheck-vulndb 0.0.20260317T205859-150000.1.152.1 SUSE-SU-2026:1042-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/steveiliop56/tinyauth < 1.0.1-20260311144920-9eb2d33064b7 1.0.1-20260311144920-9eb2d33064b7 GHSA-xg2q-62g2-cvcm
Go github.com/steveiliop56/tinyauth all versions — GO-2026-4689

Advisories 2

References