High severity7.5NVD Advisory· Published Sep 15, 2026· Updated Sep 16, 2026

CVE-2026-91985

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.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected packages

Versions sourced from the GitHub Security Advisory.

Package	Affected versions	Patched versions
code.vikunja.io/apiGo	< 2.6.0	2.6.0

Affected products

Go Vikunja/Vikunjallm-fuzzy
Range: <2.6.0
ghsa-coords
pkg:golang/code.vikunja.io/api
Range: < 2.6.0

Patches

Vulnerability mechanics

References

News mentions

Go Vikunja: Twelve Vulnerabilities Including Privilege Escalation and Auth Bypass Disclosed Together
Vypr Intelligence · Sep 15, 2026

Severity

HighCVSS v3.1

7.5/ 10

CVSS v48.7

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack vector: Network
Complexity: Low
Privileges: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Vector

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

Affected

Source repo: github.com/go-vikunja/vikunja

EPSS

Probability of exploitation in the next 30 days.

0.43%

VYPR risk score

Composite of severity, exploitation, and reach.

0.42medium

cvss	0.488
epss	0.000
exploit	0.000
kev	0.000
patch	-0.070
ransomware	0.000

Weaknesses

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

CVE ID

CVE-2026-91985

Credits

0
0xcelien
reporter · ghsa
J
JellowBeanz26
reporter · ghsa
Y
ybsun0215
reporter · ghsa