5.5

CVE-2025-66548: nextcloud deck Improper Encoding or Escaping of Output

CVSS: 5.5v3.1MediumAnalyzed
Published 05-12-2025Last modified 08-12-2025
Open JSON

Vulnerability summary

CVE-2025-66548 is a medium (CVSS 5.5) Improper Encoding or Escaping of Output vulnerability in nextcloud deck. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 4.1% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.15%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 05-12-2025
    PublishedVulnerability first disclosed.
  2. 08-12-2025
    Last modifiedVulnerability information updated.

Description

Nextcloud Deck is a kanban style organization tool aimed at personal planning and project organization for teams integrated with Nextcloud. Prior to 1.12.7, 1.14.4, and 1.15.1, file extension can be spoofed by using RTLO characters, tricking users into download files with a different extension than what is displayed. This vulnerability is fixed in 1.12.7, 1.14.4, and 1.15.1.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.15%

Chance of exploitation in the next 30 days

Percentile

4%

Versus all other CVEs

30-day change

0.00 pp

From 0.15% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.15%

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

Nextcloud2 products
  • deck< 1.12.7 | ≥ 1.14.0, < 1.14.4 | ≥ 1.15.0, < 1.15.1
  • security-advisories≥ 1.15.0-beta.1, < 1.15.1 | ≥ 1.14.0-beta.1, < 1.14.4 | < 1.12.7

1 vendor · 2 products

References

4 links