CVE-2026-91985

EUVD-2026-78656
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Common Weakness Enumeration
References
https://github.com/go-vikunja/vikunja/security/advisories/GHSA-qfwc-vx6f-3g6g
https://www.vulncheck.com/advisories/vikunja-before-2.6.0-privilege-escalation-via-link-share-hash
https://github.com/go-vikunja/vikunja/security/advisories/GHSA-qfwc-vx6f-3g6g