4.3

CVE-2026-77170: nextcloud deck Improper Access Control

CVSS: 4.3v3.0MediumDeferred
Published 18-09-2026Last modified 18-09-2026
Open JSON

Vulnerability summary

CVE-2026-77170 is a medium (CVSS 4.3) Improper Access Control vulnerability in nextcloud deck. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 17.9% of scored vulnerabilities.

Overall risk
17/100
0100
Low · default modelHow is this calculated?
CVSS score
4.3/10
010
Medium · v3.0 (CVE.org)
EPSS score
0.27%
0%100%
Low · +0.12 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 18-09-2026
    PublishedVulnerability first disclosed.
  2. 18-09-2026
    Last modifiedVulnerability information updated.

Description

The Deck config API allows authenticated users to set board-scoped configuration keys for arbitrary board IDs without validating whether the user owns or has permission to manage the referenced board.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.27%

Chance of exploitation in the next 30 days

Percentile

18%

Versus all other CVEs

30-day change

+0.12 pp

From 0.15% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.27%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Nextcloud1 product
  • deck≥ 1.16.0, ≤ 1.18.0

1 vendor · 1 product

References

1 links