How severe is CVE-2026-25555?

CVE-2026-25555 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-25555 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (71st percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-25555?

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-2026-25555 have an EU (EUVD) identifier?

Yes. CVE-2026-25555 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35138.

When was CVE-2026-25555 published?

CVE-2026-25555 was published on 2026-06-08 and last updated on 2026-06-17.

CVE-2026-25555

CVE-2026-25555 is a critical-severity vulnerability with a CVSS 3.x base score of 9.8. 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-305.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 9.3
EPSS exploit prediction: 2% (71st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-35138
Weakness: CWE-305
Published: 2026-06-08
Last modified: 2026-06-17

Description

OpenBullet2 through version 0.3.2 contains an authentication bypass vulnerability in the API key authentication middleware that allows unauthenticated attackers to gain admin access by supplying an empty X-Api-Key header value. Attackers can exploit the middleware's comparison of the supplied header against an empty AdminApiKey default string to access the admin console and all API endpoints without valid credentials.

Frequently asked questions

What is CVE-2026-25555?: OpenBullet2 through version 0.3.2 contains an authentication bypass vulnerability in the API key authentication middleware that allows unauthenticated attackers to gain admin access by supplying an empty X-Api-Key header value. Attackers can exploit the middleware's comparison of the supplied header against an empty AdminApiKey default string to access the admin console and all API endpoints without valid credentials.
How severe is CVE-2026-25555?: CVE-2026-25555 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-25555 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-25555?: 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-2026-25555 have an EU (EUVD) identifier?: Yes. CVE-2026-25555 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35138.
When was CVE-2026-25555 published?: CVE-2026-25555 was published on 2026-06-08 and last updated on 2026-06-17.

References

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