How severe is CVE-2026-30956?

CVE-2026-30956 has a CVSS 3.x base score of 9.9, rated critical 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-2026-30956 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-30956?

CVE-2026-30956 affects Hackerbay Oneuptime. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-30956?

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.

Does CVE-2026-30956 have an EU (EUVD) identifier?

Yes. CVE-2026-30956 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10559.

When was CVE-2026-30956 published?

CVE-2026-30956 was published on 2026-03-10 and last updated on 2026-06-17.

CVE-2026-30956

CVE-2026-30956 is a critical-severity vulnerability in Hackerbay Oneuptime with a CVSS 3.x base score of 9.9. 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-285.

Key facts

Severity: Critical (CVSS 3.x base score 9.9)
EPSS exploit prediction: 0% (39th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-10559
Weakness: CWE-285
Affected product: Hackerbay Oneuptime
Published: 2026-03-10
Last modified: 2026-06-17

Description

OneUptime is a solution for monitoring and managing online services. Prior to 10.0.21, a low‑privileged user can bypass authorization and tenant isolation in OneUptime v10.0.20 and earlier by sending a forged is-multi-tenant-query header together with a controlled projectid header. Because the server trusts this client-supplied header, internal permission checks in BasePermission are skipped and tenant scoping is disabled. This allows attackers to access project data belonging to other tenants, read sensitive User fields via nested relations, leak plaintext resetPasswordToken, and reset the victim’s password and fully take over the account. This results in cross‑tenant data exposure and full account takeover. This vulnerability is fixed in 10.0.21.

Frequently asked questions

What is CVE-2026-30956?: OneUptime is a solution for monitoring and managing online services. Prior to 10.0.21, a low‑privileged user can bypass authorization and tenant isolation in OneUptime v10.0.20 and earlier by sending a forged is-multi-tenant-query header together with a controlled projectid header. Because the server trusts this client-supplied header, internal permission checks in BasePermission are skipped and tenant scoping is disabled. This allows attackers to access project data belonging to other tenants, read sensitive User fields via nested relations, leak plaintext resetPasswordToken, and reset the victim’s password and fully take over the account. This results in cross‑tenant data exposure and full account takeover. This vulnerability is fixed in 10.0.21.
How severe is CVE-2026-30956?: CVE-2026-30956 has a CVSS 3.x base score of 9.9, rated critical 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-2026-30956 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-30956?: CVE-2026-30956 affects Hackerbay Oneuptime. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-30956?: 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.
Does CVE-2026-30956 have an EU (EUVD) identifier?: Yes. CVE-2026-30956 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10559.
When was CVE-2026-30956 published?: CVE-2026-30956 was published on 2026-03-10 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:hackerbay:oneuptime:*:*:*:*:*:*:*:*

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