How severe is CVE-2026-61398?

CVE-2026-61398 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-61398 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-61398?

CVE-2026-61398 affects Apache Cloudstack. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-61398?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2026-61398 published?

CVE-2026-61398 was published on 2026-08-21 and last updated on 2026-08-27.

CVE-2026-61398

CVE-2026-61398 is a critical-severity vulnerability in Apache Cloudstack with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-116.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-116
Affected product: Apache Cloudstack
Published: 2026-08-21
Last modified: 2026-08-27

Description

Improper Encoding or Escaping of Output vulnerability in Apache CloudStack's UI while using Instance Reset Password functionality. This issue affects Apache CloudStack: from 4.15.1.0 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.

Frequently asked questions

What is CVE-2026-61398?: Improper Encoding or Escaping of Output vulnerability in Apache CloudStack's UI while using Instance Reset Password functionality. This issue affects Apache CloudStack: from 4.15.1.0 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.
How severe is CVE-2026-61398?: CVE-2026-61398 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-61398 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-61398?: CVE-2026-61398 affects Apache Cloudstack. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-61398?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-61398 published?: CVE-2026-61398 was published on 2026-08-21 and last updated on 2026-08-27.

References

https://lists.apache.org/thread/g6cwddtjrwbh1d56wjz4cfp3fzfm4kbc

Affected products (1)

cpe:2.3:a:apache:cloudstack:*:*:*:*:*:*:*:*

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