How severe is CVE-2025-26042?

CVE-2025-26042 has a CVSS 3.x base score of 6.0, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity high, and availability high.

Is CVE-2025-26042 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-26042?

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

Does CVE-2025-26042 have an EU (EUVD) identifier?

Yes. CVE-2025-26042 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-6495.

When was CVE-2025-26042 published?

CVE-2025-26042 was published on 2025-03-17 and last updated on 2026-06-17.

CVE-2025-26042

CVE-2025-26042 is a medium-severity vulnerability with a CVSS 3.x base score of 6.0. 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-1333.

Key facts

Severity: Medium (CVSS 3.x base score 6.0)
EPSS exploit prediction: 0% (29th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-6495
Weakness: CWE-1333
Published: 2025-03-17
Last modified: 2026-06-17

Description

Uptime Kuma >== 1.23.0 has a ReDoS vulnerability, specifically when an administrator creates a notification through the web service. If a string is provided it triggers catastrophic backtracking in the regular expression, leading to a ReDoS attack.

Frequently asked questions

What is CVE-2025-26042?: Uptime Kuma >== 1.23.0 has a ReDoS vulnerability, specifically when an administrator creates a notification through the web service. If a string is provided it triggers catastrophic backtracking in the regular expression, leading to a ReDoS attack.
How severe is CVE-2025-26042?: CVE-2025-26042 has a CVSS 3.x base score of 6.0, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity high, and availability high.
Is CVE-2025-26042 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-26042?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-26042 have an EU (EUVD) identifier?: Yes. CVE-2025-26042 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-6495.
When was CVE-2025-26042 published?: CVE-2025-26042 was published on 2025-03-17 and last updated on 2026-06-17.

References

Other CWE-1333 vulnerabilities

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CVE-2023-29487 — Critical (CVSS 9.1): An issue was discovered in Heimdal Thor agent versions 3.4.2 and before on Windows and 2.6.9 and before on macOS,…
CVE-2026-47138 — High (CVSS 8.7): Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to…
CVE-2025-6998 — High (CVSS 8.7): ReDoS in strip_whitespaces() function in cps/string_helper.py in Calibre Web and Autocaliweb allows unauthenticated…

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