How severe is CVE-2026-31271?

CVE-2026-31271 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-2026-31271 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-31271?

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-2026-31271 have an EU (EUVD) identifier?

Yes. CVE-2026-31271 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19765.

When was CVE-2026-31271 published?

CVE-2026-31271 was published on 2026-04-07 and last updated on 2026-06-17.

CVE-2026-31271

CVE-2026-31271 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-288.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (42nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-19765
Weakness: CWE-288
Published: 2026-04-07
Last modified: 2026-06-17

Description

megagao production_ssm v1.0 contains an authorization bypass vulnerability in the user addition functionality. The insert() method in UserController.java lacks authentication checks, allowing unauthenticated attackers to create super administrator accounts by directly accessing the /user/insert endpoint. This leads to complete system compromise.

Frequently asked questions

What is CVE-2026-31271?: megagao production_ssm v1.0 contains an authorization bypass vulnerability in the user addition functionality. The insert() method in UserController.java lacks authentication checks, allowing unauthenticated attackers to create super administrator accounts by directly accessing the /user/insert endpoint. This leads to complete system compromise.
How severe is CVE-2026-31271?: CVE-2026-31271 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-2026-31271 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-31271?: 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-2026-31271 have an EU (EUVD) identifier?: Yes. CVE-2026-31271 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19765.
When was CVE-2026-31271 published?: CVE-2026-31271 was published on 2026-04-07 and last updated on 2026-06-17.

References

https://github.com/clockw1se0v0/Vul/blob/main/production_ssm/Unauthorized.md

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