CVE-2026-91985Public exploitNetwork attack vectorHinoki check available

Privilege escalation via disclosed link-share hash

Published Sep 15, 2026 · Updated Sep 15, 2026

Missing authorization in Vikunja before 2.6.0 allows remote authenticated users to escalate project privileges via a disclosed link-share hash. LinkSharing.CanRead delegates single-share reads to project.CanRead, then the v1 and v2 handlers serialize the share's bearer hash to any project reader. Read-level project membership and an existing link share are required; exchanging the hash for a link-share JWT grants the share's write or admin permissions.

CVSS severityUnavailable
Unscored
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Missing authorization in Vikunja before 2.6.0 allows remote authenticated users to escalate project privileges via a disclosed link-share hash. LinkSharing.CanRead delegates single-share reads to project.CanRead, then the v1 and v2 handlers serialize the share's bearer hash to any project reader. Read-level project membership and an existing link share are required; exchanging the hash for a link-share JWT grants the share's write or admin permissions.

The record

CVE
CVE-2026-91985
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
Vikunja
Product
Vikunja
Classifications
CWE-862, CWE-639, CWE-200, T1068
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <2.6.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Vikunja · Vikunjaversion=0 <2.6.0

Published CVSS scores

No CVSS assessment is available in this record.

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.

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

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-862Missing Authorization
CWE-639Authorization Bypass Through User-Controlled Key
CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1068Exploitation for Privilege Escalation

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo