How severe is CVE-2026-90535?

CVE-2026-90535 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-90535 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-90535?

CVE-2026-90535 affects Flowiseai Flowise. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-90535?

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.

When was CVE-2026-90535 published?

CVE-2026-90535 was published on 2026-09-12 and last updated on 2026-09-15.

CVE-2026-90535

CVE-2026-90535 is a high-severity vulnerability in Flowiseai Flowise with a CVSS 3.x base score of 7.5. 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-862.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 6.3
EPSS exploit prediction: 0% (39th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-862
Affected product: Flowiseai Flowise
Published: 2026-09-12
Last modified: 2026-09-15

Description

Flowise versions before 3.1.4 contain an unauthenticated denial of service vulnerability in the /api/v1/text-to-speech/abort endpoint that accepts user-supplied chatflowId and chatId without ownership verification. Attackers can terminate active chatflow predictions for any user by submitting requests with known chatflow and chat identifiers, causing targeted service disruption.

Frequently asked questions

What is CVE-2026-90535?: Flowise versions before 3.1.4 contain an unauthenticated denial of service vulnerability in the /api/v1/text-to-speech/abort endpoint that accepts user-supplied chatflowId and chatId without ownership verification. Attackers can terminate active chatflow predictions for any user by submitting requests with known chatflow and chat identifiers, causing targeted service disruption.
How severe is CVE-2026-90535?: CVE-2026-90535 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-90535 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-90535?: CVE-2026-90535 affects Flowiseai Flowise. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-90535?: 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.
When was CVE-2026-90535 published?: CVE-2026-90535 was published on 2026-09-12 and last updated on 2026-09-15.

References

Affected products (1)

cpe:2.3:a:flowiseai:flowise:*:*:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

18.228.228.159 (ipv4-addr)
3.19.213.118 (ipv4-addr)