How severe is CVE-2026-8078?

CVE-2026-8078 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-8078 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-8078?

CVE-2026-8078 primarily affects Checkmk. In total, 157 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-8078?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-8078 have an EU (EUVD) identifier?

Yes. CVE-2026-8078 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35052.

When was CVE-2026-8078 published?

CVE-2026-8078 was published on 2026-06-08 and last updated on 2026-06-17.

CVE-2026-8078

CVE-2026-8078 is a medium-severity vulnerability in Checkmk with a CVSS 3.x base score of 4.8. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 4.8)
CVSS v4: 4.8
EPSS exploit prediction: 0% (4th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-35052
Weakness: CWE-79
Affected product: Checkmk
Published: 2026-06-08
Last modified: 2026-06-17

Description

Stored cross-site scripting in the global settings change log in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an administrator who can change global settings to store malicious HTML or JavaScript in changelog messages that executes in other users' browsers when they view the Activate Changes page or Audit log.

Frequently asked questions

What is CVE-2026-8078?: Stored cross-site scripting in the global settings change log in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an administrator who can change global settings to store malicious HTML or JavaScript in changelog messages that executes in other users' browsers when they view the Activate Changes page or Audit log.
How severe is CVE-2026-8078?: CVE-2026-8078 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-8078 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-8078?: CVE-2026-8078 primarily affects Checkmk. In total, 157 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-8078?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-8078 have an EU (EUVD) identifier?: Yes. CVE-2026-8078 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35052.
When was CVE-2026-8078 published?: CVE-2026-8078 was published on 2026-06-08 and last updated on 2026-06-17.

References

https://checkmk.com/werk/17992

Affected products (157)

cpe:2.3:a:checkmk:checkmk:2.2.0:-:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b1:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b2:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b3:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b4:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b5:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b6:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b7:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b8:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:i1:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p1:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p10:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p11:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p12:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p13:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p14:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p15:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p16:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p17:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p18:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p19:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p2:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p20:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p21:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p22:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p23:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p24:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p25:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p26:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p27:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p28:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p29:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p3:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p30:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p31:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p32:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p33:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p34:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p35:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p36:*:*:*:*:*:*

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