CVE-2026-57458Public exploitNetwork attack vectorHinoki check available

Scope bypass via OAuth session credential issuance

Published Oct 9, 2026 · Updated Oct 9, 2026

Scope bypass in Vikunja 2.3.0 OAuth allows remote authenticated users to access out-of-scope API routes via token exchange. HandleAuthorize accepts an API-token-authenticated principal as an OAuth resource owner and issues a code that the token endpoint exchanges for a JWT and refresh token without retaining the original permission limits. Exploitation requires a token granting oauth.authorize; demonstrated access remains within the same user's account, with no validated cross-user access or escalation to administrator.

CVSS severity8.1
High
EPSS probability0.27%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Scope bypass in Vikunja 2.3.0 OAuth allows remote authenticated users to access out-of-scope API routes via token exchange. HandleAuthorize accepts an API-token-authenticated principal as an OAuth resource owner and issues a code that the token endpoint exchanges for a JWT and refresh token without retaining the original permission limits. Exploitation requires a token granting oauth.authorize; demonstrated access remains within the same user's account, with no validated cross-user access or escalation to administrator.

The record

CVE
CVE-2026-57458
Published
Oct 9, 2026
Updated
Oct 9, 2026
Vendor
Vikunja
Product
Vikunja
Classifications
CWE-269, T1550.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 9, 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== 2.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Vikunja · Vikunjaversion== 2.3.0

Published CVSS scores

8.1GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-269Improper Privilege Management
T1550.001Application Access Token

Public exploit references

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Technologies

Your stack

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