CVE-2026-32245Public exploitNetwork attack vector

Cross-client impersonation via unbound authorization codes

Published Mar 12, 2026 · Updated Mar 12, 2026

Incorrect authorization in Tinyauth before 5.0.3 allows remote authenticated users to impersonate users across OIDC clients. The token handler retrieves an authorization-code entry and validates its redirect URI, but fails to compare the stored client ID with the authenticated requesting client's ID before issuing tokens. Exploitation requires multiple configured clients and access to another client's authorization code; single-client deployments are unaffected.

CVSS severity6.5
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in Tinyauth before 5.0.3 allows remote authenticated users to impersonate users across OIDC clients. The token handler retrieves an authorization-code entry and validates its redirect URI, but fails to compare the stored client ID with the authenticated requesting client's ID before issuing tokens. Exploitation requires multiple configured clients and access to another client's authorization code; single-client deployments are unaffected.

The record

CVE
CVE-2026-32245
Published
Mar 12, 2026
Updated
Mar 12, 2026
Vendor
Tinyauth
Product
Tinyauth
Classifications
CWE-863, T1550.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 12, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 5.0.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Tinyauth · Tinyauthversion=< 5.0.3

Published CVSS scores

6.5GitHubCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:H/A:N
6.5NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1550.001Use Alternate Authentication Material: Application Access Token

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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