How severe is CVE-2026-40351?

CVE-2026-40351 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-2026-40351 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-40351?

CVE-2026-40351 affects Fastgpt. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-40351?

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-2026-40351 have an EU (EUVD) identifier?

Yes. CVE-2026-40351 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23557.

When was CVE-2026-40351 published?

CVE-2026-40351 was published on 2026-04-17 and last updated on 2026-06-17.

CVE-2026-40351

CVE-2026-40351 is a critical-severity vulnerability in Fastgpt 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-943.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-23557
Weakness: CWE-943
Affected product: Fastgpt
Published: 2026-04-17
Last modified: 2026-06-17

Description

FastGPT is an AI Agent building platform. In versions prior to 4.14.9.5, the password-based login endpoint uses TypeScript type assertion without runtime validation, allowing an unauthenticated attacker to pass a MongoDB query operator object (e.g., {"$ne": ""}) as the password field. This NoSQL injection bypasses the password check, enabling login as any user including the root administrator. This issue has been fixed in version 4.14.9.5.

Frequently asked questions

What is CVE-2026-40351?: FastGPT is an AI Agent building platform. In versions prior to 4.14.9.5, the password-based login endpoint uses TypeScript type assertion without runtime validation, allowing an unauthenticated attacker to pass a MongoDB query operator object (e.g., {"$ne": ""}) as the password field. This NoSQL injection bypasses the password check, enabling login as any user including the root administrator. This issue has been fixed in version 4.14.9.5.
How severe is CVE-2026-40351?: CVE-2026-40351 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-2026-40351 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-40351?: CVE-2026-40351 affects Fastgpt. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-40351?: 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-2026-40351 have an EU (EUVD) identifier?: Yes. CVE-2026-40351 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23557.
When was CVE-2026-40351 published?: CVE-2026-40351 was published on 2026-04-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:fastgpt:fastgpt:*:*:*:*:*:*:*:*

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