Is CVE-2026-31271 in the CISA KEV catalog?

No. CVE-2026-31271 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-31271?

CVE-2026-31271 has a CVSS v3 base score of 9.8 (CRITICAL).

What is the EPSS score for CVE-2026-31271?

CVE-2026-31271 has an EPSS score of 0.55% (42th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-31271

CRITICAL

9.8

CVSS v3

NVD

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.

CWE-288

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

0.55%probability of exploitation in 30 days

42ndpercentile

Moderate risk: more likely to be exploited than 42% of all known CVEs.

References

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

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-09.