How severe is CVE-2026-55477?

CVE-2026-55477 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-55477 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-55477?

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.

Does CVE-2026-55477 have an EU (EUVD) identifier?

Yes. CVE-2026-55477 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39432.

When was CVE-2026-55477 published?

CVE-2026-55477 was published on 2026-06-25.

CVE-2026-55477

CVE-2026-55477 is a high-severity vulnerability with a CVSS 3.x base score of 7.2. 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-73.

Key facts

Severity: High (CVSS 3.x base score 7.2)
EPSS exploit prediction: 0% (26th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-39432
Weakness: CWE-73
Published: 2026-06-25
Last modified: 2026-06-25

Description

3X-UI is a web control panel for managing Xray-core servers. Prior to 3.3.1, an authenticated administrator can abuse the database import functionality to achieve arbitrary file write on the host by modifying Xray configuration values stored in the database. This can be leveraged to obtain code execution and persistent access as the user running Xray (including root when Xray is running as root). This vulnerability is fixed in 3.3.1.

Frequently asked questions

What is CVE-2026-55477?: 3X-UI is a web control panel for managing Xray-core servers. Prior to 3.3.1, an authenticated administrator can abuse the database import functionality to achieve arbitrary file write on the host by modifying Xray configuration values stored in the database. This can be leveraged to obtain code execution and persistent access as the user running Xray (including root when Xray is running as root). This vulnerability is fixed in 3.3.1.
How severe is CVE-2026-55477?: CVE-2026-55477 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-55477 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-55477?: 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.
Does CVE-2026-55477 have an EU (EUVD) identifier?: Yes. CVE-2026-55477 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39432.
When was CVE-2026-55477 published?: CVE-2026-55477 was published on 2026-06-25.

References

https://github.com/MHSanaei/3x-ui/security/advisories/GHSA-jm48-m3rr-9hgg

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