How severe is CVE-2021-39173?

CVE-2021-39173 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-39173 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-39173?

CVE-2021-39173 affects Catchethq Catchet. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-39173?

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

When was CVE-2021-39173 published?

CVE-2021-39173 was published on 2021-08-27 and last updated on 2026-06-17.

CVE-2021-39173

CVE-2021-39173 is a high-severity vulnerability in Catchethq Catchet with a CVSS 3.x base score of 8.8. 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-704.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-704
Affected product: Catchethq Catchet
Published: 2021-08-27
Last modified: 2026-06-17

Description

Cachet is an open source status page system. Prior to version 2.5.1 authenticated users, regardless of their privileges (User or Admin), can trick Cachet and install the instance again, leading to arbitrary code execution on the server. This issue was addressed in version 2.5.1 by improving the middleware `ReadyForUse`, which now performs a stricter validation of the instance name. As a workaround, only allow trusted source IP addresses to access to the administration dashboard.

Frequently asked questions

What is CVE-2021-39173?: Cachet is an open source status page system. Prior to version 2.5.1 authenticated users, regardless of their privileges (User or Admin), can trick Cachet and install the instance again, leading to arbitrary code execution on the server. This issue was addressed in version 2.5.1 by improving the middleware `ReadyForUse`, which now performs a stricter validation of the instance name. As a workaround, only allow trusted source IP addresses to access to the administration dashboard.
How severe is CVE-2021-39173?: CVE-2021-39173 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-39173 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-39173?: CVE-2021-39173 affects Catchethq Catchet. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-39173?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-39173 published?: CVE-2021-39173 was published on 2021-08-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:catchethq:catchet:*:*:*:*:*:*:*:*

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CVE-2021-39174 — High (CVSS 8.8): Cachet is an open source status page system. Prior to version 2.5.1, authenticated users, regardless of their…
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