4.8

CVE-2026-61399: apache software foundation apache cloudstack Improper Encoding or Escaping of Output

CVSS: 4.8v3.1MediumAnalyzed
Published 21-08-2026Last modified 24-08-2026
Open JSON

Vulnerability summary

CVE-2026-61399 is a medium (CVSS 4.8) Improper Encoding or Escaping of Output vulnerability in apache software foundation apache cloudstack. EPSS estimates a 0.50% chance of exploitation in the next 30 days, higher than 41.6% of scored vulnerabilities.

Overall risk
19/100
0100
Low · default modelHow is this calculated?
CVSS score
4.8/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.50%
0%100%
Low · +0.22 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 21-08-2026
    PublishedVulnerability first disclosed.
  2. 24-08-2026
    Last modifiedVulnerability information updated.

Description

Improper Encoding or Escaping of Output vulnerability in Apache CloudStack's UI while using Lock User Functionality. This issue affects Apache CloudStack: from 4.20.0.0 through 4.20.3.0 and from 4.21.0.0 through 4.22.1.0. Users are recommended to upgrade to version 4.20.3.1 or 4.22.1.1 or later, which fixes the issue.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.50%

Chance of exploitation in the next 30 days

Percentile

42%

Versus all other CVEs

30-day change

+0.22 pp

From 0.28% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.50%

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

Apache1 product
  • cloudstack≥ 4.20.0.0, < 4.20.3.1 | ≥ 4.21.0.0, < 4.22.1.1
Apache software foundation1 product

2 vendors · 2 products

References

1 links