Vulnerability · Published Sep 15, 2026 · Assigned by VulnCheck

CVE-2026-91985Vikunja before 2.6.0 Privilege Escalation via Link Share Hash

High 7.5

In plain English

A high-severity information exposure in vikunja from go-vikunja. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.4%top 62.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Vikunja before 2.6.0 fails to properly restrict access to the link-share hash field in single-share read endpoints, allowing read-only members to obtain the share's secret credential. Attackers can exchange the disclosed hash for a link-share JWT at the share's permission level to escalate privileges and perform unauthorized writes or administrative actions.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	code.vikunja.io/api	2.6.0	GHSA-qfwc-vx6f-3g6g
Go	code.vikunja.io/api	no fix listed	GO-2026-6747

Affected products (as reported)

Vendor	Product	Versions
go-vikunja	vikunja	0 – before 2.6.0

Weakness: CWE-200 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

GitHub Security Advisory (GHSA-qfwc-vx6f-3g6g) vendor-advisory
VulnCheck Advisory: Vikunja before 2.6.0 Privilege Escalation via Link Share Hash third-party-advisory