How severe is CVE-2026-33455?

CVE-2026-33455 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-33455 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33455?

CVE-2026-33455 primarily affects Checkmk. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-33455?

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

Does CVE-2026-33455 have an EU (EUVD) identifier?

Yes. CVE-2026-33455 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21342.

When was CVE-2026-33455 published?

CVE-2026-33455 was published on 2026-04-10 and last updated on 2026-06-17.

CVE-2026-33455

CVE-2026-33455 is a medium-severity vulnerability in Checkmk with a CVSS 3.x base score of 6.3. 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-140.

Key facts

Severity: Medium (CVSS 3.x base score 6.3)
CVSS v4: 5.3
EPSS exploit prediction: 0% (7th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-21342
Weakness: CWE-140
Affected product: Checkmk
Published: 2026-04-10
Last modified: 2026-06-17

Description

Livestatus injection in the monitoring quicksearch in Checkmk <2.5.0b4 allows an authenticated attacker to inject livestatus commands via the search query due to insufficient input sanitization in search filter plugins.

Frequently asked questions

What is CVE-2026-33455?: Livestatus injection in the monitoring quicksearch in Checkmk <2.5.0b4 allows an authenticated attacker to inject livestatus commands via the search query due to insufficient input sanitization in search filter plugins.
How severe is CVE-2026-33455?: CVE-2026-33455 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-33455 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33455?: CVE-2026-33455 primarily affects Checkmk. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-33455?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-33455 have an EU (EUVD) identifier?: Yes. CVE-2026-33455 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21342.
When was CVE-2026-33455 published?: CVE-2026-33455 was published on 2026-04-10 and last updated on 2026-06-17.

References

https://checkmk.com/werk/17988

Affected products (3)

cpe:2.3:a:checkmk:checkmk:2.5.0:b1:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.5.0:b2:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.5.0:b3:*:*:*:*:*:*

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Other CWE-140 vulnerabilities

CVE-2025-32918 — High (CVSS 8.8): Improper neutralization of Livestatus command delimiters in autocomplete endpoint within the RestAPI of Checkmk…
CVE-2024-38865 — High (CVSS 8.8): Improper neutralization of livestatus command delimiters in a specific endpoint within RestAPI of Checkmk prior to…
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CVE-2026-33456 — High (CVSS 7.6): Livestatus injection in the notification test mode in Checkmk <2.5.0b4 and <2.4.0p26 allows an authenticated user with…
CVE-2023-6157 — High (CVSS 7.6): Improper neutralization of livestatus command delimiters in ajax_search in Checkmk <= 2.0.0p39, < 2.1.0p37, and <…
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