CVE-2026-91985

high

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.

References

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

Details

Source: Mitre, NVD

Published: 2026-09-15

Updated: 2026-09-16

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:N/A:N

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Severity: High

CVSS v4

Base Score: 8.7

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.00381